Evaluation of presence of and vulnerability to atrial fibrillation and other indications using matrix metalloproteinase-based imaging

ABSTRACT

The invention provides, in some embodiments, methods relating to assessing increased risk of developing atrial fibrillation (AF), and/or the likelihood of responding to particular AF therapies using imaging agents comprising an MMP inhibitor linked to an imaging moiety. The invention further provides methods for evaluating the presence of the risk of developing other cardiovascular conditions and assessing the effectiveness of treatment or other intervention for such conditions by determining MMP levels.

BACKGROUND OF INVENTION

Atrial fibrillation (AF) is a disturbance in the rhythmic beating (orarrhythmia) of the upper chambers of the heart. AF is the most commonsustained cardiac arrhythmia, responsible for almost 50% ofhospitalizations for arrhythmias (Benjamin E J, et al. 1998; Wyse D G,et al. 2002; Benjamin E J, et al. 1997; Allessie M A, et al. 2001).Consequently, AF is a significant cause of morbidity and mortality andtreatment of AF has been hampered by the ineffectiveness of availabledrugs. Moreover, attempts to terminate AF with electrical shocks, usinga process termed “cardioversion” works for only about one-half of thepatients during the first 6-12 months. Therefore, a “simple” means toidentify patients in whom cardioversion would effectively terminate AFwould be beneficial in terms of saved time and money. Moreover, a meansto identify patients that may or may not benefit from an implantablepacer, pharmacological rate and/or rhythm control therapy and/orablation would also be beneficial.

SUMMARY OF INVENTION

The invention is broadly based on the use of matrix metalloproteinase(MMP) based imaging to detect the presence of (including early detectionof) and/or the risk of developing certain cardiovascular conditions andto evaluate the efficacy of therapies and/or other interventionsdirected towards such conditions. MMP levels (and thus activity) can bedetected using in vivo medial imaging techniques. In accordance with theinvention, MMP activation is an indicator of tissue (e.g., vascular)remodeling, and such remodeling is an indicator of certain conditions oran indicator of developing certain conditions.

Thus, the invention is premised, in part, on the surprising finding thatMMP levels (and activity) can be detected at early time periods,including prior to the onset of certain cardiovascular conditions suchas but not limited to myocardial fibrosis, AF, calcific aortic valvedisease (CAVD), and atherosclerosis. It has not been heretofore knownthat MMP levels could be detected at such early time points and thatdetection at these early time points correlated with increased risk of,for example, AF and CAVD. The invention therefore provides, inter alia,methods for determining increased risk (or likelihood, as the terms areused interchangeably herein) of developing, for example, AF or CAVDbased on detection and/or quantification of MMP levels, and morespecifically localized MMP levels such as cardiac MMP levels.

In one aspect, the invention provides a method for evaluating the riskof developing AF comprising administering to a subject an imaging agentcomprising a matrix metalloproteinase (MMP) inhibitor linked to animaging moiety and obtaining a cardiac image.

In some embodiments, the subject has experienced a cardiovascular insultsuch as, but not limited to, a myocardial infarction and/or heartsurgery and/or has been diagnosed as having a cardiovascular diseasesuch as but not limited to coronary artery disease, heart valve disease,cardiomyopathy, and/or congenital heart disease. If the subject hasexperienced a cardiovascular insult, the method may be performed withindays, or within a week, or within 2 weeks, or within a month, or within2 months of the cardiovascular insult. In some embodiments, the methodmay be performed within 10 days of the cardiovascular insult. In someembodiments, the subject does not have a history of AF (i.e., thesubject has not been heretofore diagnosed as having AF), although thesubject may have been diagnosed with other cardiovascular diseases asstated above. In some embodiments, the subject may have a familialhistory of AF and/or the subject may present with certain risk factorsthat are associated with an increased risk of developing AF. Such riskfactors include high blood pressure and chronic lung disease.

In these and other aspects of the invention, the method may be performedonce on the subject or it may be performed repeatedly on the subject inorder to monitor the subject over a period of time.

In another aspect, the invention provides a method for evaluating therisk of AF recurrence (e.g., following cardioversion therapy). Themethod comprises administering to a subject previously diagnosed with AFand treated with an AF therapy an imaging agent of the invention, andobtaining an image of the heart of the subject, in whole or in part. Insome embodiments, the above-normal levels (including in some instancesmere presence) of MMP following cardioversion therapy indicate anincreased risk of AF recurrence (e.g., following cardioversion). In someembodiments, the AF therapy may be cardioversion, pharmacological rateand/or rhythm control, an implantable pacer, and the like.

In another aspect, the invention provides a method for identifying in asubject having a history of AF the likelihood of responding to treatmentwith an implantable pacer. The method comprises administering to asubject previously diagnosed with AF an imaging agent of the invention,and obtaining an image of the heart of the subject, in whole or in part.The above-normal levels (including in some instances mere presence) ofMMP identify the subject as one to be treated with an implantable pacer.

In another aspect, the invention provides a method for identifying in asubject having a history of AF the likelihood of responding topharmacological rate control therapy. The method comprises administeringto a subject previously diagnosed with AF an imaging agent of theinvention, and obtaining an image of the heart of the subject, in wholeor in part. The above-normal levels (including in some instances merepresence) of MMP identify the subject as one to be treated usingpharmacological rate control therapy. Such therapies includebeta-blockers, calcium antagonists, and digoxin.

In another aspect, the invention provides a method for identifying in asubject having a history of AF the likelihood of responding topharmacological rhythm control therapy. The method comprisesadministering to a subject previously diagnosed with AF an imaging agentof the invention, and obtaining an image of the heart of the subject, inwhole or in part. The above-normal levels (including in some instancesmere presence) of MMP identify the subject as one to be treated usingpharmacological rhythm control therapy. Such therapies includebeta-blockers, amiodarone, class Ic agents, and sotalol.

In another aspect, the invention provides a method for identifying in asubject having a history of AF the likelihood of responding to ablationtherapy. The method comprises administering to a subject previouslydiagnosed with AF an imaging agent of the invention, and obtaining animage of the heart of the subject, in whole or in part. The above-normallevels (including in some instances the mere presence) of MMP identifythe subject as one to be treated using ablation therapy.

In some embodiments, the subject having a history of AF is a subjectthat has experienced an AF event. In some embodiments, the subjecthaving a history of AF is a subject that has experienced recurrent AF.

The image indicates the presence or absence of imaging agent in theheart of the subject which in turn indicates the level (or amount ofMMP) in the heart of the subject. In some embodiments, the imageindicates the amount of the imaging agent in the heart of the subject,in whole or in part. In some embodiments, the image comprises atrialmyocardium, including the left atrial myocardium, of the subject.

In some embodiments, the MMP inhibitor has an inhibitory constant K_(i)of <1000 nM. In some embodiments, the MMP inhibitor has an inhibitoryconstant K_(i) of <100 nM. In some embodiments, the MMP inhibitor is aninhibitor of one or more matrix metalloproteinases selected from thegroup consisting of MMP-2, MMP-9 and MMP-14.

In some embodiments, the imaging agent is

(referred to herein as ^(99m)Tc-RP805).

In some embodiments, the imaging agent is

(referred to herein as ¹¹¹In-RP782).

In some embodiments, the imaging agent of the invention is selected fromthe group consisting of:

wherein F represents an isotopically-enriched population of ¹⁸F, andvariants thereof comprising, instead of F, an isotopically-enrichedimaging moiety selected from the group consisting of ¹¹C, ¹³N, ¹²³I,¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹²¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga. That is, insome embodiments, F is replaced with an isotopically-enriched imagingmoiety or a chelator associated with an isotopically-enriched imagingmoiety, wherein the imaging moiety is selected from the group consistingof ¹¹C, ¹³N, ¹²³I, ¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and⁶⁸Ga.

Other suitable imaging agents for MMP detection and quantitation aredescribed herein.

In some embodiments, the method further comprises determining myocardialperfusion in the subject. Myocardial perfusion may be determined byobtaining an image of the heart, in whole or in part, using a myocardialperfusion imaging agent. Suitable myocardial perfusion imaging agentsinclude flurpiridaz F 18 injection(4-chloro-2-(1,1-dimethylethyl)-5-({4-[(2-[¹⁸F]fluoroethoxy)methyl]phenyl}methoxy)pyridazin-3(2H)-one),^(99m)Tc sestamibi (Tc99m[MIBI]₆ where MIBI is 2-methoxy isobutylisonitrile), ²⁰¹Thallium, and the like. In some embodiments, myocardialperfusion is quantitated. In some embodiments, an index is determinedthat comprises a measure of myocardial perfusion and a measure of MMPlevel based on the obtained images. In some embodiments, the indexderives from a logisitic regression analysis of the summed rest scoreand the MMP level. In some embodiments, the measure of myocardialperfusion is the summed stress score. In some embodiments, the measureof perfusion is the summed rest score. In some embodiments, the measureof perfusion is the summed difference score.

In some embodiments, the MMP image and/or the myocardial perfusion imageis obtained before the subject exhibits any signs of myocardialfibrosis. The presence of myocardial fibrosis may be determined using,for example, delayed enhancement MRI of the heart in whole or in part.

In another aspect, the invention provides a compound having a structureselected from the group consisting of

wherein F represents an isotopically-enriched population of ¹⁸F, andvariants thereof comprising, instead of F, an isotopically enrichedimaging moiety selected from the group consisting of ¹¹C, ¹³N, ¹²³I,¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga.

In another aspect, the invention provides a composition comprising anyof the foregoing compounds, and a pharmaceutically acceptable carrier.

In another aspect, the invention provides use or methods of use of theforegoing compounds in medical imaging techniques.

In another aspect, the invention provides methods for determining thepresence of an atherosclerotic plaque in a subject comprisingadministering to a subject an imaging agent comprising an MMP inhibitorlinked to an imaging moiety and acquiring an image of a portion of thesubject (e.g., an image of the cardiovasculature); and determining thepresence of an atherosclerotic plaque at least in part based on thepresence of an increased amount of imaging agent in the imaged portionof the subject (for example, as compared to a region that does notcontain an atherosclerotic plaque).

In another aspect, the invention provides methods for determining theeffectiveness of an anti-lipid therapy on atherosclerosis (e.g., onatherosclerotic plaque biology or morphology) in a subject comprisingadministering to a subject a first dose of an imaging agent comprisingan MMP inhibitor linked to an imaging moiety and acquiring at least onefirst image of a portion of the subject; administering an anti-lipidtherapy to the subject; administering a second dose of an imaging agentcomprising an MMP inhibitor linked to an imaging moiety to the subjectand acquiring at least one second image of a portion of the subject;determining the change in the amount of imaging agent in the portion ofthe subject between the at least one first image and the at least onesecond image; and determining the effectiveness of the anti-lipidtherapy based at least in part on the change in the amount of theimaging agent in the portion of the subject between the first image andthe second image. The portion of the subject being imaged is typicallythe cardiovasculature such as the coronary arteries and the like.

In another aspect, the invention provides methods of determining thepresence of calcific aortic valve disease (CAVD) in a subject and/ordetermining a subject's risk of developing CAVD comprising administeringto a subject an imaging agent comprising an MMP inhibitor linked to animaging moiety and acquiring a first cardiac image of the subject; anddetermining the presence of CAVD and/or a subject's risk of developingCAVD based at least in part on the first cardiac image. The cardiacimage typically includes or is of the cardiac valve, optionallyincluding the leaflets. In accordance with the invention, increaseduptake of the imaging agent in the aortic valve region is indicative ofthe presence of CAVD or the increased risk of developing CAVD. In someembodiments, the subject being imaged does not have atherosclerosis(e.g., the subject does not manifest symptoms associated withatherosclerosis, and is referred to as “asymptomatic” for thiscondition). The uptake of an MMP inhibitor linked to an imaging moietyin a particular portion of a subject can allow for the imaging of tissueremodeling characterized in part by macrophage infiltration, MMPactivation, and the like, in a portion of the subject, as a diagnosticindicator of CAVD.

In another aspect, the invention provides methods of determining theprogression of CAVD in a subject comprising administering to the subjecta first dose of an imaging agent comprising an MMP inhibitor linked toan imaging moiety and acquiring at least one first cardiac image of thesubject; administering a second dose of an imaging agent comprising anMMP inhibitor linked to an imaging moiety and acquiring at least onesecond cardiac image of the subject; determining the change in theamount of imaging agent in the heart or a portion of the heart betweenthe first image and the second image; and determining the progression ofCAVD in the subject based at least in part on the change in the amountof the imaging agent in the heart or the portion of the heart betweenthe at least one first image and the at least one second image. Inimportant embodiments, the image includes or is of the aortic valve,optionally including the leaflets. In some embodiments, the methodcomprises administering more than two doses of the imaging agent,obtaining more than two cardiac images, and determining the progressionof CAVD based at least in part on the change in the amount of theimaging agent in the heart or the portion of the heart between theobtained images.

In another aspect, the invention provides methods of determining theeffectiveness of a treatment for CAVD in a subject comprisingadministering to a subject a first dose of an imaging agent comprisingan MMP inhibitor linked to an imaging moiety and acquiring at least onefirst cardiac image of the subject; administering a treatment for CAVDto the subject; administering a second dose of an imaging agentcomprising an MMP inhibitor linked to an imaging moiety and acquiring atleast one second cardiac image of the subject; determining the change inthe amount of imaging agent in the heart or a portion of the heartbetween the first image and the second image; and determining theeffectiveness of the treatment for CAVD based at least in part on thechange in the amount of the imaging agent in the heart or a portion ofthe heart between the at least one first image and the at least onesecond image. In important embodiments, the image includes or is of theaortic valve, optionally including the leaflets. The inventioncontemplates that effectiveness of the treatment will be evidenced by adecreased amount (and in some instances a constant or unchanged amount)of imaging agent in the heart, and in particular in the aortic valveregion, optionally including the leaflets.

In various imaging methods set forth herein, two or more images may beobtained from a subject. This may be the case where for example thesubject is undergoing a treatment and/or other intervention betweenimages or where it is desired to monitor the progression of or towards acondition in the absence of treatment or significant intervention.Treatment may be an anti-lipid therapy, although it is not so limited.Intervention may be a change in lifestyle, including for example weightloss, cessation of smoking, increased exercise, and the like, althoughit too is not so limited. When two or more images are obtained from asubject, the images may be randomly spaced or regularly spaced in time,including for example about weekly, biweekly, monthly, bimonthly, every6 months, or yearly.

These and other aspects of the invention will be described in greaterdetail herein.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1. Comparison of myocardial ²⁶¹Tl and ^(99m)Tc-RP805 activity withMMP zymography in pig hearts 1, 2, and 4 weeks post-MI. Shown are colorcoded spatial maps of relative myocardial ²⁰¹Tl activity (top row),^(99m)Tc-RP805 activity (second row), MMP-9 activity assessed byzymography (third row), total and active MMP-2 activity assessed byzymography (fourth and fifth rows), MMP-7 levels (sixth row), MT1-MMPlevels (seventh row), and MMP activity determined as a function ofcleavage of a fluorescent substrate (seventh row). Images are orientedwith the lateral wall on the right. Note the time dependent changes inregional ^(99m)Tc-RP805 activity correlate with spatial and temporalchanges in MMP levels/activity as assessed by zymography. Referencecolor bar is at the bottom. Relationship between in vivo and in vitrodetermination of MMP activity (upper right). In vivo MMP activity,determined as retention of ^(99m)Tc-RP805, was significantly related toin vitro changes in levels of active MMP-2 (y=1687e^(0.033x), r: 0.89,p<0.05). (lower right) There was a significant relationship between thechange in body mass indexed LV end-diastolic volume relative to controlvalues and MMP activity within the MI region (y=31.34e0.48x, r=0.38,p=0.04).

FIG. 2. In vivo (top) and ex vivo (middle) SPECT/CT images were obtainedin control pigs (n=7) and in pigs 10 days (n=2). Increased MMPactivation is seen in infarct region and in both atria. Graph ofmyocardial RP805 uptake (% injected dose/g) for control pigs and pigs 10days and 4 weeks post-MI (bottom). There were significant increases in^(99m)Tc-RP805 uptake within both atria and infarct region at 10 dayspost-MI. At 4 weeks, post-MI infarct region remained significantlyelevated (defined as p<0.003 after Bonferonni correction to increasestringency) as did the LA region (p<0.01).

FIG. 3. Representative transaxial slices from ex vivo SPECT images of acontrol pig heart, and hearts from pigs at 1 and 2 weeks post-MI. Thetop row of each image contain are targeted ^(99m)Tc-RP805 images (lineargrey scale) matched with corresponding high resolution CT images (grayscale, below). Hearts were filled with alginate mixed with CT contrastto define right and left ventricles (RV & LV) and atria (RA & LA).Uniform uptake is seen in the control heart. Infarcted heartsdemonstrate focal ^(99m)Tc-RP805 in the infarct region and in the atria.

FIG. 4. Results from quantitative analysis of ex vivo ^(99m)Tc-RP805SPECT images from a pig heart at 4 weeks post-MI. A. Uncorrected SPECTimages, B. SPECT images with resolution recovery, C. SPECT datareconstructed with partial volume correction (PVC), D. Grey-scale^(99m)Tc-RP805 activity for 8 radial sectors per slice from gamma wellcounter, E. Postmortem images of heart demonstrating dense inferolateralscar and marked wall thinning, F. Correlation between measured regionalmyocardial well-counter activity and SPECT derived activity with PVC.

FIG. 5. Plot of the MMP total activity per unit time, according to someembodiments.

FIG. 6. Plot of the percent area collagen for the left and right regionsof the heart. Regional changes in matrix structure could be detected by1 week post-MI which were significant by 4 weeks post-MI(Kruskal-Wallis, p<0.05). In the inset: PSR Imaging revealed matrixdisruption and discontinuity between atrial myocytes which wasprogressive with time post-MI.

FIG. 7. ^(99m)Tc-RP805 in vivo microSPECT/CT imaging (left) of MMPactivation in an ApoE−/− mouse fed a Western diet for 9 months. Traceruptake in the aortic valve area is indicated by the arrows. Uptake inthe aortic valve was confirmed by ex vivo planar imaging (right) of theexplanted heart and aorta.

FIG. 8. Plot of in vivo uptake over time of 99mTc-RP805 in the aorticvalve over time in ApoE−/− mice fed a Western diet at varioustimepoints, and related data.

FIG. 9. Plot of ex vivo uptake of ^(99m)Tc-RP805 in the aortic valveover time in ApoE−/− mice fed a Western diet.

FIG. 10. Autoradiography of the explanted aorta from an ApoE−/− mousefed a Western diet for three months. Arrows indicate uptake of¹¹¹In-RP782 in the aortic valve area.

FIG. 11. H&E staining of the aortic valve in ApoE−/− mice fed a Westerndiet for 4 (left) and 9 months (right) demonstrating marked remodelingof valve leaflets over time.

FIG. 12. Immunostaining of F4-80 (dark grey) in the aortic valve from anApoE−/− mouse fed a Western diet for 6 months demonstrating considerablemacrophage infiltration.

FIG. 13. Plots of aortic valve GAPDH-normalized CD68 (top) and MMP-12(bottom) mRNA expression quantified by real time RT-PCR in wild type(WT) mice on normal chow and ApoE−/− mice fed a Western diet for 3, 6 or9 months.

FIG. 14. Grey scale-coded non contrast CT images of an ApoE−/− mouse feda Western diet for 10 months demonstrating calcification of the aorticvalve. Arrows indicate the aortic valve plane.

FIG. 15. M mode echocardiographic images of ApoE−/− mice fed a Westerndiet demonstrating normal systolic separation of aortic valve cuspsafter 3 months on diet (left) and reduced separation after 9 months(right).

DETAILED DESCRIPTION OF INVENTION

The invention is based, in part, on the unexpected finding that MMPlevels, and in some instances more specifically cardiovascular MMPlevels, aortic valve MMP levels, and/or cardiac MMP levels, can beobserved using, for example, MMP inhibitors linked to imaging moieties,and that such MMP levels can be used to evaluate the presence of(including early detection of) or the likelihood of developing certainconditions, the progression of the condition, and the effectiveness oftreatments and/or interventions directed towards such conditionsincluding prophylactic or therapeutic treatments. The inventioncontemplates that increased MMP levels (and thus increased MMP activity)is indicative of tissue (e.g., vascular) remodeling observed in certaincardiovascular conditions and/or that predisposes certain cardiovascularconditions such as but not limited to AF.

Some aspects of the invention relate to determining the presence of orthe risk of developing AF. In some embodiments, cardiac MMP levels areindicative of whether a subject is likely to develop AF, either as aprimary event or as a recurrence. The methods of the invention can beused to identify subjects having an increased risk (as compared to therisk of control or “normal” subjects) of developing AF. Subjectsidentified in this manner may then be monitored more closely (includingmore regularly) or they may be treated at an earlier time point thanpreviously contemplated in order to reduce the risk that AF willultimately develop. In some embodiments, any increased MMP levelrelative to control is used to identify subjects at increased risk. Insome embodiments, the MMP level (over control level) is used to quantifythe risk of developing AF. In these latter instances, lower MMP levelsmay correlate with lower risk and higher MMP levels may correlate withhigher risk of AF. It is to be understood that MMP levels may beindicated by retention levels of MMP imaging agents of the invention.

The invention also contemplates a method for determining a treatmentregimen for a subject having AF as well as a method of determining thelikelihood of response to a treatment in a subject having a history ofAF. The method comprises administering to a subject (having AF and/orhaving a history of AF) an imaging agent of the invention and obtaininga heart (cardiac) image of the subject, wherein the MMP level in thesubject indicates whether the subject should be treated using electricalcardioversion or an alternative treatment such as pharmacological rateor rhythm management, ablation and/or an implantable rate device. Theinvention thus provides, in some embodiments, methods to direct theclinical management strategy of such AF subjects between rate control(including pharmacological rate control) or rhythm control (includingdevice-based and/or pharmacological rhythm control) treatments.

The invention further contemplates a method for determining the extentand complexity of ablation therapy that may be needed to treat AF in asubject.

MMPs and AF

Atrial fibrosis is a hallmark of structural remodeling that contributesto the AF substrate. Left atrial tissue has been shown in patients andin animal models of AF to contain deposits of fibrillar collagen andexpansion of the extracellular matrix (ECM). Histologically determinedextent of fibrosis and ECM expansion has been shown to correlate with AFpersistence (Circ 2004; 109:363-368). Delayed enhancement MRI has beenused to image left atrial fibrosis and has shown more fibrosis inpatients with persistent AF compared to paroxysmal AF (Circ CardiovascImaging 2010; 3:231-239). As significant fibrosis is relativelypermanent, there would be greater clinical benefit to detecting thepresence and extent of more proximate pathologies. The role that MMPsplay in ECM remodeling suggests their utility in this context. Indeed,in a canine model of heart failure, administration of an MMP inhibitorattenuated the vulnerability to AF and reduced atrial fibrosis comparedto control animals (J Cardiac Failure 2008; 14:768-776). In patients inwhom pharmacologic or electrical cardioversion was attempted, refractoryAF was significantly associated with elevated MMP-2 levels (Europace2009; 11:332-337). US 2011/0009861 discloses methods of predicting AFrecurrence comprising detecting specified amounts of MMPs in bodyfluids.

The methods of this invention provide non-invasive methods to evaluatelevels of MMPs in the atria and in so doing ensure the relevant originof the MMP. As MMPs play a role in numerous normal and pathologicprocesses, MMP levels measured in a body fluid cannot be assured torepresent MMP levels in the atrium. Additionally, the spatial extent ofMMP activity, as may be determined using the methods of this invention,will predict the spatial extent of fibrosis. Such spatial extent cannotbe determined by a body fluid measure.

Provided are profiles of quantities, intensities, concentrations,spatial distribution and/or localization of an imaging agent comprisingan MMP inhibitor that are an indication of increased risk of developingprimary or recurrent AF. The profiles that are indication of higher riskof recurrence of AF in a subject can be relative to a normal value. Anormal value of an imaging agent comprising an MMP inhibitor can be areference value for an age matched subject that is confirmed to have noevidence of significant cardiovascular disease, or of AF. Thus, thenormal value can be a population-based value derived from a significantnumber of healthy individuals. These reference normal values can beobtained from population based studies.

Methods are also provided for determining whether a subject with ahistory of AF should be treated with an implantable pacer. These methodscan comprise measuring retention of an imaging agent comprising an MMPinhibitor in the subject to produce a retention profile (that acts as asurrogate for MMP levels). The produced profile can be used todetermine, inter alia, whether the subject will have a recurrence of AFfollowing a therapy such as a cardioversion procedure, a likelyrecurrence of AF indicating treatment with an implantable pacer.

Prognosis

Provided herein is a method of predicting recurrence of AF in a subject,comprising measuring retention of an imaging agent, comprising an MMPinhibitor in a subject and comparing said levels to reference values.

As used herein “recurrence” can include paroxysmal, persistent, andchronic episodes of AF in a subject that has experienced a prior episodeof AF and may or may not have been treated (including successfullytreated in the short term) for the prior episode of AF. Predictingrecurrence of AF in a subject with a history of (including presentingwith) AF can be done prior to administration of AF treatment and todetermine if the selected AF treatment will likely be followed byrecurrence of AF in that subject. For example, the recurrence of AF canbe predicted prior to electrical cardioversion. If it is determined thatelectrical cardioversion will correct the AF without recurrence of AFthen electrical cardioversion can be selected as the treatment modalityof choice. If it is determined that electrical cardioversion will notresult in sustained AF correction, then another treatment modality canbe selected. For example, an implantable pacer device can be selected orpharmacological pacing can be used instead of electrical cardioversionif it is determined that there will be recurrence with electricalcardioversion. Moreover, retention level of an imaging agent comprisingan MMP inhibitor can be used to select treatment with an implantablepacer device, ablation, or by pharmacological pacing.

The method of the invention can further comprise the steps of measuringa ventricular perfusion defect and measuring uptake of an imaging agentcomprising an MMP inhibitor. Thus, the method can comprise performing aresting flurpiridaz F 18 perfusion study, determining the summed restscore from said study, quantifying atrial uptake of an imaging agentcomprising an MMP inhibitor and determining risk of recurrent AF.

The invention further contemplates using cardiovascular MMP levels toevaluate conditions other than AF. In some embodiments, MMP levels maybe useful for determining the presence of atherosclerotic plaques in asubject and/or the effectiveness of anti-lipid therapies (e.g., employedfor the treatment of atherosclerosis) on plaque biology in a subject. Insome embodiments, cardiac MMP levels (including levels in the aorticvalve region) can be used to determine the presence of CAVD in asubject, to determine a subject's risk of developing CAVD, to determineprogression of CAVD in a subject, and/or to determine the effectivenessof a treatment for CAVD in a subject. These and other aspects andembodiments of the invention will be described in greater detail herein.

MMPs and Atherosclerosis

Atherosclerosis, a major cause of morbidity and mortality in the US, islinked to hyperlipidemia. Pharmacologic treatment of hyperlipidemia is acommon treatment for atherosclerotic diseases and is believed to berelated at least in part to “stabilizing” effects on atheroscleroticplaque biology. The term “atherosclerosis” is given its ordinary meaningin the art and refers to a disease of the arterial wall in which thewall area thickens, causing narrowing of the channel and thus impairingblood flow. Atherosclerosis may occur in any area of the body, but canbe most damaging to a subject when it occurs in the heart, brain, orblood vessels leading to the brain stem. Atherosclerosis includesthickening and hardening of arterial walls or the accumulation of fat,cholesterol and other substances that form atheromas or plaques.Atherosclerosis may also result from calcification, hemorrhage,ulceration, thrombosis, and/or trauma.

As noted above, in some embodiments, the invention provides non-invasivemethods to evaluate levels of MMPs in a portion of a subject. In someembodiments, imaging of MMPs (e.g., MMP activation in vivo) may be usedto determine the presence of an atherosclerotic plaque in a subject. Insome embodiments, serial imaging of MMPs (e.g., MMP activation in vivo)may be used to determine the effectiveness of an anti-lipid therapy onplaque biology in a subject. For example, a series of images may beobtained during and/or following the course of administration of atreatment for atherosclerosis to a subject, and the images may beanalyzed to determine effectiveness of the treatment. An efficacioustreatment is indicated by a reduced level of MMP activation in theimaged region. An efficacious treatment may also be indicated by anunchanged level of MMP activation in the imaged region, in someinstances. A non-efficacious treatment is indicated by an increasedlevel of MMP activation in the imaged region, in some instances.

In some embodiments, a method of determining the presence of anatherosclerotic plaque in a subject comprises administering to thesubject an imaging agent comprising an MMP inhibitor linked to animaging moiety and acquiring at least one first image of a portion ofthe subject. The presence of an atherosclerostic plaque may bedetermined based on the amount of imaging agent present in the imagedportion of the subject. In some cases, the portion of the subject is theheart or a portion of the heart (e.g., the aortic arch).

In some embodiments, the location and/or concentration of MMPsdetermined from the images may be analyzed relative to a normal value. Anormal value of an imaging agent of the invention can be a referencevalue for an age-matched subject that is confirmed to have no evidenceof significant atherosclerosis. Thus, the normal value can be apopulation-based value derived from a significant number of healthyindividuals. These reference normal values can be obtained frompopulation-based studies. The normal value may be determined based onimaging agent uptake in the aortic arch.

In some embodiments, a method of determining the effectiveness of ananti-lipid therapy on plaque biology in a subject comprisesadministering to the subject a first dose of an imaging agent comprisingan MMP inhibitor linked to an imaging moiety and acquiring at least onefirst image of a portion of the subject. An anti-lipid therapy may thenbe administered to the subject. Following and/or concurrent toadministration of the anti-lipid therapy, the subject may beadministered a second dose of an imaging agent comprising an MMPinhibitor linked to an imaging moiety and at least one second image of aportion of the subject may be acquired. The change (e.g., decreaseand/or increase) in the amount of imaging agent in the portion of thesubject between the first image and the second image may be determined.The effectiveness of the anti-lipid therapy may be determined based atleast in part on the change in the amount of the imaging agent in theportion of the subject between the first image and the second image. Insome cases, a decrease in the amount of imaging agent in the portion ofthe subject indicates that the anti-lipid therapy is effective inreducing the amount of plaque in the subject. In some cases, the portionof the subject is the heart or a portion of the heart. In some cases,the change in the amount of imaging agent in the aortic arch may beanalyzed/determined. In some cases, a lack of an increase in the amountof imaging agent in the imaged portion of the subject (i.e., a constantlevel or a decreased level) may also indicate an effective anti-lipidtherapy.

In some embodiments, the subject may be administered additional doses ofan imaging agent comprising an MMP inhibitor linked to an imaging moietyand additional images of a portion of the subject may be acquired. Thechange in the amount of imaging agent in the portion of the subjectbetween two images, or more than two images, may be used to determinethe effectiveness of the anti-lipid therapy.

Those of ordinary skill in the art will be aware of anti-lipid therapieswhich may be used to treat atherosclerosis in a subject, for example,statins (e.g., rosuvastatin), fibrates (e.g., gemfibrozil, fenofibrate),dietary changes, etc.

In some important embodiments, the imaging agent comprises thestructure:

wherein F represents an isotopically-enriched population of ¹⁸F, andvariants thereof comprising, instead of F, an isotopically enrichedimaging moiety selected from the group consisting of ¹¹C, ¹³N, ¹²³I,¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga.

MMPs and Calcific Aortic Valve Disease (CAVD)

Calcific aortic valve disease (CAVD) is common among the elderlypopulation. Inflammation and matrix remodeling play a central role inprogression of CAVD to symptomatic aortic stenosis. MMPs are upregulatedin CAVD. Generally, the term “calcific aortic valve disease” encompassesa disease spectrum from initial alterations in the cell biology of theleaflets to end-stage calcification resulting in left ventricularoutflow obstruction. Disease progression is generally characterized by aprocess of thickening of the valve leaflets and the formation of calciumnodules—often including the formation of actual bone—and new bloodvessels, which are concentrated near the aortic surface. End-stagedisease, e.g., calcific aortic stenosis, is generally characterizedpathologically by large nodular calcific masses within the aortic cuspsthat protrude along the aortic surface into the sinuses of Valsalva,interfering with opening of the cusps.

As noted above, in some embodiments, the invention provides non-invasivemethods to evaluate levels of MMPs in a portion of the subject. In someembodiments, imaging of MMPs (e.g., MMP activation in vivo) can be usedto determine the presence of CAVD in a subject (including earlydetection and/or diagnosis prior to irreversible injury), to determine asubject's risk of developing CAVD, to determine progression of CAVD in asubject, and/or to determine the effectiveness of a treatment for CAVDin subject. For example, a single image may be obtained of a subject,wherein the image may be analyzed to determine the presence of CAVD in asubject and/or the subject's risk of developing CAVD. As anotherexample, a series of images may be obtained of a subject over a periodof time, wherein the images may be analyzed to determining theprogression of CAVD in the subject and/or the effectiveness of atreatment for CAVD.

In some embodiments, a method of determining the presence of CAVD in asubject and/or determining a subject's risk of developing CAVD comprisesadministering to the subject an imaging agent comprising an MMPinhibitor linked to an imaging moiety and acquiring a first cardiacimage of the subject. The presence of CAVD in the subject and/or thesubject's risk of developing CAVD may be based at least in part on thefirst cardiac image. In some cases, the amount of imaging agent in theaortic valve may be analyzed/determined. In some embodiments, thesubject is asymptomatic for atherosclerosis.

The images and related MMP values may be analyzed relative to a normalvalue. A normal value of an imaging agent comprising an MMP inhibitorcan be a reference value for an age-matched subject that is confirmed tohave no evidence of significant CAVD. Thus, the normal value can be apopulation-based value derived from a significant number of healthyindividuals. These reference normal values can be obtained frompopulation-based studies. The normal value may be determined based onthe level of imaging agent uptake in a portion of the heart (e.g.,aortic valve).

In some embodiments, the images obtained of a portion of a subject(e.g., of a subject's aortic valve) may be analyzed in connection withand/or with reference to other images or data obtained from the subject.For example, in some cases, the images obtained of a subject's aorticvalve indicating MMP levels may be analyzed in connection with and/orwith reference to a CT scan of the subject's aortic valve, wherein theCT may indicate the presence or absence of calcification of thesubject's aortic valve. Other non-limiting examples including asubject's cholesterol levels (e.g. LDL levels), blood pressure, and/orcardiac dysfunction (e.g., as determined by ultrasound or EKG). In somecases, the subject may have been diagnosed as having or as being at riskof developing CAVD and/or atherosclerosis. In other cases, the subjectmay be asymptomatic and/or may have not been diagnosed as having CAVDand/or atherosclerosis. In some instances, the images obtained using forexample another imaging agent and/or another modality may provide noevidence of calcification and thus the subject may be one that manifestsno calcification and yet is experiencing the early stages of CAVD (i.e.,precalcification stages of CAVD).

In some embodiments, a method of determining the progression of CAVD ina subject comprises administering to the subject a first dose of animaging agent comprising an MMP inhibitor linked to an imaging moietyand acquiring at least one first cardiac image of the subject. At alater time point, the subject may be administered a second dose of animaging agent comprising an MMP inhibitor linked to an imaging moietyand at least one second cardiac image of the subject may be acquired.The change (e.g., decrease and/or increase) in the amount of imagingagent in the heart or a portion of the heart between the first image andthe second image may be determined. The progression of CAVD in a subjectmay be determined based at least in part on the change in the amount ofthe imaging agent in the heart or a portion of the heart between thefirst image and the second image. In some cases, the change in theamount of imaging agent in the aortic valve may be analyzed/determined.

In some embodiments, a method of determining the effectiveness of atreatment for CAVD in a subject comprises administering to a subject afirst dose of an imaging agent comprising an MMP inhibitor linked to animaging moiety and acquiring at least one first cardiac image of thesubject. The treatment for CAVD may then be administered to the subject.Following and/or concurrent to administration of the treatment for CAVD,the subject may be administered a second dose of an imaging agentcomprising an MMP inhibitor linked to an imaging moiety and at least onesecond cardiac image of the subject may be acquired. The change (e.g.,decrease and/or increase) in the amount of imaging agent in the heart ora portion of the heart between the first image and the second image maybe determined. The effectiveness of the treatment for CAVD may bedetermined based at least in part on the change in the amount of theimaging agent in the heart or a portion of the heart between the firstimage and the second image. In some cases, the lack of an increase inthe amount of the imaging agent in the imaged portions of the subjectmay indicate effectiveness of the treatment. In some cases, the changein the amount of imaging agent in the aortic valve may beanalyzed/determined.

In some embodiments, the imaging agent is ^(99m)Tc-RP805 or ¹¹¹In-RP782.In some important embodiments, the imaging agent comprises thestructure:

wherein F represents an isotopically-enriched population of ¹⁸F, andvariants thereof comprising, instead of F, an isotopically-enrichedimaging moiety selected from the group consisting of ¹¹C, ¹³N, ¹²³I,¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga.

Imaging Agents

The imaging agents of the invention comprise an MMP inhibitor linked toan imaging moiety. Localization of the MMP inhibitor (e.g., throughbinding to MMP resident in a tissue) is indicative of the MMP levelwhich in turn is indicative of MMP activity. As will be understood, MMPinhibitor presence, location and/or amount is detected by virtue of theimaging moiety linked to the MMP inhibitor.

MMP inhibitors refer to agents that bind to one or more MMPs. The MMPsmay be but are not limited to MMP-2, MMP-9 and/or MMP-14. Preferably,the MMP inhibitors bind to one or more MMPs for a period of time that issufficient to detect their presence in the tissue being imaged.

As used herein, an “imaging moiety” refers to an atom or group of atomsthat is capable of producing a detectable signal itself or upon exposureto an external source of energy (e.g., imaging agents comprising imagingmoieties may allow for the detection, imaging, and/or monitoring of thepresence and/or progression of a condition), pathological disorder,and/or disease. Nuclear medicine imaging agents can include ¹¹C, ¹³N,¹⁸F, ¹²³I, ¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga asthe imaging moiety. In some embodiments, the imaging moiety is ¹⁸F.

In some embodiments, a compound (e.g., an imaging agent, a fluoridespecies) may be isotopically-enriched with fluorine-18.“Isotopically-enriched” refers to a composition containing isotopes ofan element such that the resultant isotopic composition is other thanthe natural isotopic composition of that element. With regard to thecompounds provided herein, when a particular atomic position isdesignated as ¹⁹F, it is to be understood that the abundance of ¹⁹F atthat position is substantially greater than the natural abundance of¹⁸F, which is essentially zero. In some embodiments, a fluorinedesignated as ¹⁸F may have a minimum isotopic enrichment factor of about0.01%, about 0.05%, about 0.1%, about 0.2%, about 0.3%, about 0.4%,about 0.5%, about 0.75%, about 1%, about 2%, about 3%, about 4%, about5%, about 10%, about 15%, about 20%, about 30%, about 40%, about 50%,about 60%, about 70%, about 80%, about 90%, about 95%, or greater. Theisotopic enrichment of the compounds provided herein can be determinedusing conventional analytical methods known to one of ordinary skill inthe art, including mass spectrometry and HPLC.

Imaging moieties include, without limitation, radioisotopes,paramagnetic metal atoms, gas-filled microspheres, and the like. It willbe understood that the nature of the imaging moiety will depend in largepart on the imaging modality to be used. As an example, imaging moietiesthat are radioisotopes are known to be useful for imaging by gammascintigraphy or positron emission tomography (PET), and thus would besuitable if such imaging modalities were being used in the methods ofthe invention. As another example, the imaging moiety may be a metallicradioisotope or a paramagnetic metal atom suitable for magneticresonance imaging (MRI). In these instances, the MMP inhibitor may belinked to one or more chelators, and the imaging moiety binds to thechelator(s). In these instances, the imaging moiety is non-covalentlylinked to the MMP inhibitor via the chelator. As yet another example,the MMP inhibitor may be linked to gas-filled microspheres whenultrasound is the imaging modality of choice. The MMP inhibitor may belinked to the material that encapsulates and/or stabilizes suchmicrospheres. In an important embodiment, the imaging moiety is ¹⁸F.

Each MMP inhibitor may be linked to one or more imaging moieties. TheMMP inhibitors may be directly or indirectly linked to an imagingmoiety. Indirect linkage may involve the use of a linker or a spacer.Linkage may be covalent or non-covalent. In important embodiments,covalent linkage is preferred.

Imaging agents suitable for use in the methods of the invention areshown below along with their precursors:

Imaging Agent Precursors Imaging Agents

The imaging agents of Table 1 may be synthesized from the precursorsalso shown in Table 1. LG refers to the leaving group and may be but isnot limited to tosylates and mesylates. Methods for synthesizing imagingagents from tosylate or other precursor forms are described in publishedPCT application WO 2011/097649.

Other imaging agents suitable for use in the methods of the inventioninclude those described in U.S. Pat. No. 6,656,448 and in U.S. Pat. No.6,989,139, the specific teachings of which are incorporated by referenceherein.

Those of ordinary skill in the art will be aware of methods forsynthesizing the imaging agents and imaging agent precursors describedherein. For example, see the methods disclosed in the Examples sectionas well as those described in U.S. Pat. No. 6,656,448 and in U.S. Pat.No. 6,989,139, the specific teachings of which are incorporated byreference herein.

Some imaging agents suitable for use in the methods of the inventioninclude those having one of the two following structures:

wherein, R is independently OH or —CH₂SH; R¹ is independently selectedat each occurrence from the group: H, OH, C₁-C₃ alkyl, C₂-C₃ alkenyl,C₂-C₃ alkynyl, and heterocycle-S—CH₂—; R² is independently C₁-C₂₀ alkyl;X is independently C═O or SO₂ provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶; R⁴ isindependently selected at each occurrence from the group: C1-C6 alkyl,phenyl, and benzyl; R⁵ is independently at each occurrence from thegroup:

NH(C1-C6 alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl,phenyl and heterocycle groups are optionally substituted with a bond tothe linking group or a bond to the chelator; R⁶ is independently aryloxysubstituted with 0-3 R⁷; R⁷ is independently halogen or methoxy;

or alternatively, R¹ and R⁴ may be taken together to form a bridginggroup of the formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted witha bond to the linking group or a bond to the chelator; or alternatively,R¹ and R² may be taken together to form a bridging group of the formula—(CH₂)₃—NH—, optionally substituted with a bond to the linking group ora bond to the chelator; or R¹ and R² taken together with the nitrogenand carbon atom through which they are attached form a C₅₋₇ atomsaturated ring system substituted with one or more substituents selectedfrom the group consisting of: a bond to L_(n), where L_(n) is a linkinggroup between the matrix metalloproteinase inhibitor and chelator a bondto C_(h), and —C═O—NR²⁹R³⁰; where C_(h) is a chelator, R⁸ isindependently at each occurrence OH or phenyl, optionally substitutedwith a bond to the linking group or a bond to the chelator, providedthat when R⁸ is phenyl, R¹⁰ is —C(═O)—CR¹²—NH—CH(CH₃)—COOH; R⁹ andR^(9′) are independently H, C1-C6 alkyl optionally substituted with abond to the linking group or a bond to the chelator, or are takentogether with the carbon atom to which R⁹ and R^(9′) are attached toform a 5-7 atom saturated, partially unsaturated or aromatic ring systemcontaining 0-3 heteroatoms selected from O, N, SO₂ and S, said ringsystem substituted with R⁶ and optionally substituted with a bond to thelinking group or a bond to the chelator; R¹⁰ and R¹¹ are independentlyH, or C1-C6 alkyl optionally substituted with a bond to the linkinggroup or a bond to the chelator, or are taken together with the nitrogenatom to which they are attached to form a 5-7 atom saturated, partiallyunsaturated or aromatic ring system containing 0-3 heteroatoms selectedfrom O, N, SO₂ and S, said ring system optionally substituted with 0-3R²⁷, a bond to the linking group or a bond to the chelator; oralternatively, R⁹ and R¹⁰ are taken together with the carbon atom towhich they are attached to form a 5-7 atom saturated, partiallyunsaturated or aromatic ring system containing 0-3 heteroatoms selectedfrom O, N, SO₂ and S, said ring system optionally substituted with abond to the linking group or a bond to the chelator; and R¹² isindependently C1-C20 alkyl; R²⁷ is =0, C1-4 alkyl, or phenyl substitutedwith R²⁸; R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;

R²⁹ and R³⁰ taken together with the nitrogen atom through which they areattached form a C5-7 atom saturated ring system substituted with R³¹ andR³¹ is a benzyloxy group substituted with C1-4 alkyl. In all of theforegoing embodiments, a metallic imaging moiety is chelated by thechelator.

Still other imaging agents comprise (a) an imaging moiety that is adiagnostic metal, and (b) a compound selected from

-   2-{[5-(3-{2-[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-acetylamino}propylcarbamoyl)-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonic    acid;-   2-{[5-(4-{[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-methyl}-benzylcarbamoyl)-pyridin-2-yl]-hydrazonomethyl}-benzene    sulfonic acid;-   2-[7-({N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonyl-amino}acetyl    amino)propyl]carbamoyl}methyl)-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl]acetic    acid;-   2-{7-[(N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-carbony    1-amino}methyl)phenyl]methyl}carbamoyl)methyl]-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl}acetic    acid;-   2-(7-{[N-(1-{N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonyl-amino}acetylamino)propyl]carbamoyl}-2-sulfoethyl)carbamoyl]methyl}-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl)acetic    acid;-   2-[7-({N-[1-(N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-y    1]carbonylamino}methyl)phenyl]methyl}carbamoyl)-2-sulfoethyl]carbamoyl}methyl)-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl]acetic    acid;-   2-({2-[({N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methyl    propyl)-11-oxa-5-oxo    bicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]carbamoyl}methyl)(carboxymethyl)amino}ethyl){2-[bis(carboxymethyl)amino]ethyl}amino]acetic    acid;-   2-[(2-{[(N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxo    bicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}methyl)phenyl]methyl}carbamoyl)methyl](carboxymethyl)amino}ethyl){2-[bis(carboxymethyl)amino]ethyl}amino]acetic    acid;-   N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxo    bicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonyl-amino}acetylamino)propyl]-4,5-bis[2-(ethoxyethyl-thio)acetylamino]pentanamide;-   N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxo    bicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}methyl)-phenyl]methyl}-4,5-bis[2-(ethoxyethylthio)acetylamino]-pentanamide;-   1-(1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamino)α,ω-dicarbonylPEG3400-2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}-N-(3-aminopropyl)acetamide;

1-(1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamino)α,ω-dicarbonylPEG3400-[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-N-{[4-(aminomethyl)phenyl]methyl}carboxamideconjugate;

-   2-[2-({5-[N-(5-(N-hydroxycarbamoyl)(5R)-5-{3-[4-(3,4-dimethoxyphenoxy)phenyl]-3    methyl-2-oxopyrrolidinyl}pentyl)carbamoyl](2-pyridyl)}amino)(1Z)-2-azavinyl]benzenesulfonic    acid; and-   2-(2-{[5-(N-{3-[3-(N-hydroxycarbamoyl)(4S)-4-({4-[(4-methylphenyl)methoxy]piperidyl}carbonyl)piperidyl]-3-oxopropyl}carbamoyl)(2-pyridyl)]amino}(1Z)-2-azavinyl)benzenesulfonic    acid.

Still other examples of suitable imaging agents comprise an imagingmoiety such as a diagnostic metal attached to a compound comprisingeither of the following structures:

In still yet other embodiments, the imaging agent comprises thestructure:

wherein F represents an isotopically-enriched population of ¹⁸F, andvariants thereof comprising, instead of F, an isotopically-enrichedimaging moiety selected from the group consisting of ¹¹C, ¹³N, ¹²³I,¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga. That is,wherein F is replaced with an isotopically-enriched imaging moiety or achelator associated with an isotopically-enriched imaging moiety,wherein the imaging moiety is selected from the group consisting of ¹¹C,¹³N, ¹²³I, ¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga.a. First Non-Limiting Set of Embodiments of Imaging Agents or PrecursorsThereof

This section provides non-limiting embodiments of compounds which mayfunction as imaging agents and/or imaging agent precursors. In someembodiments, a compound is provided, wherein the compound may beassociated with a radioisotope (e.g., a cytotoxic radioisotope), therebyforming an imaging agent.

(1) In some embodiments, the compound is of embodiment 1 of this firstnon-limiting set of embodiments, wherein the compound comprises:a) 1-10 targeting moietiesb) a chelator (Ch); andc) 0-1 linking groups (Ln) between the targeting moiety and chelator;wherein the targeting moiety is a matrix metalloproteinase inhibitor;andwherein the chelator is capable of conjugating to a cytotoxicradioisotope.(2) A compound according to embodiment 1, wherein the targeting moietyis a matrix metalloproteinase inhibitor having an Inhibitory constantK_(i) of <1000 nM.(3) A compound according to embodiment 1, wherein the targeting moietyis a matrix, metalloproteinase inhibitor having an inhibitory constantK_(i) of <100 nM.(4) A compound according to any one of embodiments 1-3, comprising 1-5targeting moieties.(5) A compound according to embodiment 1, comprising one targetingmoiety.(6) A compound according to any one of embodiments 1-5, wherein thetargeting moiety is a matrix metalloproteinase inhibitor of the formulae(Ia) or (Ib):

wherein,

-   R is independently OH or —CH₂SH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₂₀ alkyl;-   X is independently C═O or SO₂, provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶;

-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NR-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to the    linking group or a bond to the chelator;-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with a bond to    the linking group or a bond to the chelator;-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to the    linking group or a bond to the chelator; or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R⁸ is independently at each occurrence OH or phenyl, optionally    substituted with a bond to the linking group or a bond to the    chelator, provided that when R⁸ is phenyl, R¹⁰ is    —C(═O)—CR¹²—NH—CH(CH₃)—COOH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to the linking group or a bond to the chelator, or are    taken together with the carbon atom to which R⁹ and R^(9′) are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system substituted with R⁶ and optionally    substituted with a bond to the linking group or a bond to the    chelator;-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to the linking group or a bond to the    chelator, or are taken together with the nitrogen atom to which they    are attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system optionally substituted with 0-3 R²⁷, a    bond to the linking group or a bond to the chelator;-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system optionally substituted with a bond to    the linking group or a bond to the chelator; and-   R¹² is independently C₁₋₂₀ alkyl;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸;-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹: and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (7) A compound according to any one of embodiments 1-6 wherein the    targeting moiety is a matrix metalloproteinase inhibitor of the    formulae (Ia) or (Ib):

-   R is OH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₆ alkyl;-   X is C═O;-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to the    linking group or a bond to the chelator;-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with a bond to    the linking group or a bond to the chelator;-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to the    linking group or a bond to the chelator; or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R⁸ is OH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to the linking group or a bond to the chelator, or are    taken together with the carbon atom to which R⁹ and R^(9′) are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with a bond to the linking    group or a bond to the chelator;-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to the linking group or a bond to the    chelator, or are taken together with the nitrogen atom to which they    are attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with 0-3 R²⁷, a bond to the    linking group or a bond to the chelator;-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with a bond to the linking    group or a bond to the chelator; and-   R¹² is independently C₁₋₆ alkyl;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸;-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (8) A compound according to any one of embodiments 1-7 wherein:-   R is —OH;-   R² is C₁₋₆ alkyl;-   X is C═O;-   R³ is

-   R¹ and R⁴ are taken together to form a bridging group of formula    —(CH₂)₃—O-phenyl-CH₂—;-   R⁵ is NH(C1-6alkyl), substituted with a bond to the linking group or    a bond to the chelator.    A compound according to any one of embodiments 1-8, wherein:-   R is —OH;-   R⁹ is C₁ alkyl substituted with a bond to Ln;-   R¹⁰ and R¹¹ taken together with the nitrogen atom to which they are    attached form a 5 atom saturated ring system, said right system is    substituted with 0-3 R²⁷;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸; and-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups.    (9) A compound according to any one of embodiments 1-8, wherein:-   R is —OH;-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (10) A compound according to any one of embodiments 1-9, wherein the    linking group is of the formula:

((W¹)_(h)-(CR¹³R¹⁴)_(g))_(x)—(Z)_(k)—((CR^(13a)R^(14a))_(g′)-(W²)_(h′))_(x′);

-   W¹ and W² are independently selected at each occurrence from the    group: O, S, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O),    C(═O)O, OC(═O), NBC(═S)NH, NHC(═O)NH, SO₂, SO₂NH, —(OCH₂CH₂)₇₆₋₈₄,    (OCR₂CH₂)_(s), (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t),    and (aa)_(t′);-   aa is independently at each occurrence an amino acids-   Z is selected from the group: aryl substituted with 0-3 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-3 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, PO₃H, C₁-C₅ alkyl    substituted with 0-3 R¹⁶, aryl substituted with 0-3 R¹⁶, benzyl    substituted with 0-3 R¹⁶, and C₁-C₅ alkoxy substituted with 0-3 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to the    chelator;-   R¹⁶ is independently selected at each occurrence from the group: a    bond to the chelator, COOR¹⁷, C(═O)NHR¹⁷, NHC(═O)R¹⁷, OH, NHR¹⁷,    SO₃H, PO₃H, —OPO₃H₂, —OSO₃H, aryl substituted with 0-3 R¹⁷, C₁₋₅    alkyl substituted with 0-1 R¹⁸, C₁₋₅ alkoxy substituted with 0-1    R¹⁸, and a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R¹⁷;-   R¹⁷ is independently selected at each occurrence from the group: H,    alkyl substituted with 0-1 R¹⁸, aryl substituted with 0-1 R¹⁸, a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-1    R¹⁸, C₃₋₁₀ cycloalkyl substituted with 0-1 R¹⁸, polyalkylene glycol    substituted with 0-1 R¹⁸, carbohydrate substituted with 0-1 R¹⁸,    cyclodextrin substituted with 0-1 R¹⁸, amino acid substituted with    0-1 R¹⁸, polycarboxyalkyl substituted with 0-1 R¹⁸, polyazaalkyl    substituted with 0-1 R¹⁸, peptide substituted with 0-1 R¹⁸, wherein    the peptide is comprised of 2-10 amino acids,    3,6-O-disulfo-B-D-galactopyranosyl, bis(phosphonomethyl)glycine, and    a bond to the chelator;-   R¹⁸ is a bond to the chelator;-   k is selected from 0, 1, and 2;-   h is selected from 0, 1, and 2;-   h′ is selected from 0, 1, and 2;-   g is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s″ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   x is selected from 0, 1, 2, 3, 4, and 5; and-   x′ is selected from 0, 1, 2, 3, 4, and 5.    11. A compound according to any one of embodiments 6-10 wherein-   W¹ and W² are independently selected at each occurrence from the    group: O, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O), C(═O)O,    OC(═O), NBC(═S)NH, NHC(═O)NH, SO₂, —(CH₂CH₂O)₇₆₋₈₄—, (OCH₂CH₂)_(s),    (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t), and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-1 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-1 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-1 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, C₁-C₅ alkyl    substituted with 0-1 R¹⁶, aryl substituted with 0-1 R¹⁶, benzyl    substituted with 0-1 R¹⁶, and C₁-C₅ alkoxy substituted with 0-1 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to the    chelator;-   k is 0 or 1;-   s is selected from 0, 1, 2, 3, 4, and 5;-   s′ is selected from 0, 1, 2, 3, 4, and 5;-   s″ is selected from 0, 1, 2, 3, 4, and 5; and-   t is selected from 0, 1, 2, 3, 4, and 5.    (12) A compound according to any one of embodiments 6-11, wherein:-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (13) A compound according to any one of embodiments 6-12, wherein:-   x is 0;-   k is 1;-   Z is aryl substituted with 0-3 R¹⁶;-   g′ is 1;-   W² is NH;-   R^(13a) and R^(14a) are independently H;-   h′ is 1; and-   x′ is 1.    (14) A compound according to any one of embodiments 6-13, wherein:-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   x is 1,-   k is 0;-   g′ is 1;-   R^(13a) and R^(14a) are independently H; or C1-5 alkyl substituted    with 0-3 R¹⁶;-   R¹⁶ is SO₃H;-   W² is NHC(═O) or NH;-   h′ is 1; and-   x′ is 2.    (15) A compound according to any one of embodiments 6-14, wherein:-   W¹ is C(═O)NH;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   x is 1;-   W² is —NH(C═O)— or —(OCH₂CH₂)₇₆₋₈₄—;-   h′ is 2; and-   x′ is 1.    (16) A compound according to any one of embodiments 6-15, wherein:-   x is 0;-   k is 0;-   g′ is 3;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (17) A compound according to any one of embodiments 6-16, wherein:-   x is 0;-   z is aryl substituted with 0-3 R¹⁶;-   k is 1;-   g′ is 1;-   R^(13a)R^(14a) are independently H;-   W² is NHC(═O) or —(OCH2CH2)₇₆₋₈₄—; and-   x′ is 1.    (18) A compound according to any one of embodiments 6-17, wherein:-   W¹ is C═O;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (19) A compound according to embodiment 1 wherein the linking group    is absent.    (20) A compound according to any one of embodiments 6-19, wherein    the chelator is a metal bonding unit having a formula selected from    the group:

-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: N, NR²⁶, NR¹⁹, NR¹⁹R²⁰, S, SH,    —S(Pg), O, OH, PR¹⁹, PR¹⁹R²⁰, —O—P(O)(R²¹)—O—, P(O)R²¹R²², a bond to    the targeting moiety and a bond to the linking group;-   Pg is a thiol protecting group;-   E¹, E², E³, E⁴, E⁵, E⁶, E⁷, and E⁸ are independently a bond, CH, or    a spacer group independently selected at each occurrence from the    group: C₁-C₁₆ alkyl substituted with 0-3 R²³, aryl substituted with    0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3 R²³,    heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³, wherein the    heterocyclo group is a 5-10 membered heterocyclic ring system    containing 1-4 heteroatoms independently selected from N, S, and O,    C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀    aryl-substituted with 0-3 R²³, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O and substituted with 0-3 R²³;-   R¹⁹ and R²⁰ are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, hydrogen,    C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with 0-3    R²³, C₁₋₁₀ cycloalkyl substituted with 0-3 R²³, heterocyclo-C₁₋₁₀    alkyl substituted with 0-3 R²³, wherein the heterocyclo group is a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl    substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀ aryl-substituted with    0-3 R²³, a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³, and an electron, provided that when one of R¹⁹ or R²⁰    is an electron, then the other is also an electron;-   R²¹ and R²² are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, —OH, C₁-C₁₀    alkyl substituted with 0-3 R²³, C₁-C₁₀ alkyl substituted with 0-3    R²³, aryl substituted with 0-3 R²³, C₃₋₁₀ cycloalkyl substituted    with 0-3 R²³, heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³,    wherein the heterocyclo group is a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀    alkyl-C₆₋₁₀ aryl-substituted with 0-3 R²³, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R²³;-   R²³ is independently selected at each occurrence from the group: a    bond to the linking group, a bond to the targeting moiety, ═O, F,    Cl, Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴, —C(═O)N(R²⁴)₂, —CHO,    —CH₂OR²⁴, —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴, —OC(═O)N(R²⁴)₂,    —NR²⁵C(O)R²⁴, —NR²⁵C(═O)OR^(24a), —NR²⁵C(═O)N(R²⁴)₂,    —NR²⁵SO₂N(R²⁴)₂, —NR²⁵SO₂R^(24a), —SO₃H, —SO₂R^(24a), —SR²⁴,    —S(═O)R^(24a), —SO₂N(R²⁴)₂, —N(R²⁴)₂, —NHC(═S)NHR²⁴, —NOR²⁴, NO₂,    —C(═O)NHOR²⁴, —C(═O)NHNR²⁴R^(24a), —OCH₂CO₂H,    2-(1-morpholino)ethoxy, C₁-C₅ alkyl, C₂-C₄ alkenyl, C₃-C₆    cycloalkyl, C₃-C₆ cycloalkylmethyl, C₂-C₆ alkoxyalkyl, aryl    substituted with 0-2 R²⁴, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O, and-   wherein at least one of A¹, A², A³, A⁴, A⁵, A⁶, A⁷, A⁸ or R²³ is a    bond to the linking group or targeting moiety;-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to the linking group, a bond to the targeting    moiety, H, C₁-C₆ alkyl, phenyl, benzyl, C₁-C₆ alkoxy, halide, nitro,    cyano, and trifluoromethyl; and-   R²⁶ is a co-ordinate bond to a metal or a hydrazine protecting    group.    (21) A compound according to any one of embodiments 6-20 wherein:-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: NR¹⁹, NR¹⁹R²⁰, S, SH, OH, a bond to    the targeting moiety and a bond to the linking group;-   E¹, E², E³, E⁴, E⁵, E⁶, E⁷, and E⁸ are independently a bond, CH, or    a spacer group independently selected at each occurrence from the    group: C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with    0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3 R²³, and a 5-10    membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-3    R²³;-   wherein at least one of A¹, A², A³, A⁴, A⁵, A⁶, A⁷, A⁸ and R²³ is a    bond to the linking group or a targeting moiety;-   R¹⁹, and R²⁰ are each independently selected from the group: a bond    to the targeting moiety, a bond to the linking group, hydrogen,    C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with 0-3    R²³, a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³, and an electron, provided that when one of R¹⁹ or R²⁰    is an electron, then the other is also an electron;-   R²³ is independently selected at each occurrence from the group: a    bond to the targeting moiety, a bond to the linking group, ═O, F, C,    Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴, —C(═O)N(R²⁴)₂, —CH₂OR²⁴,    —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴, —OC(═O)N(R²⁴)₂, —NR²⁵C(═O)R²⁴,    —NR²⁵C(═O)OR^(24a), —NR²⁵C(═O)N(R²⁴)₂, —NR²⁵SO₂N(R²⁴)₂,    —NR²⁵SO₂R^(24a), —SO₃H, —SO₂R^(24a), —S(═O)R^(24a), —SO₂N(R²⁴)₂,    —N(R²⁴)₂, —NHC(═S)NHR²⁴, ═NOR¹⁸, —C(═O)NHNR¹⁸R^(18a), —OCH₂CO₂, and    2-(1-morpholino) ethoxy; and-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to the linking group, H, and C₁-C₆ alkyl.    (22) A compound according to any one of embodiments 6-21 wherein the    chelator is of the formula:

-   A¹ is a bond to the linking group;-   A², A⁴, and A⁶ are each N;-   A³, A⁵, A⁷ and A⁸ are each OH;-   E¹, E², and E⁴ are C2 alkyl;-   E³, E⁵, E⁷, and E⁸ are C₂ alkyl substituted with 0-1 R²³;-   R²³ is ═O;    (23) A compound according to any one of embodiments 6-22 wherein the    chelator is of the formula:-   C_(h) is

wherein:

-   A5 is a bond to Ln;-   A¹, A³, A⁷ and A⁸ are each OH;-   A², A⁴ and A⁶ are each NH;-   E¹, E³, E⁵, E⁷, and E⁸ are C₂ alkyl substituted with 0-1 R²³;-   E², and E⁴, are C₂ alkyl;-   R²³ is ═O.    (24) A compound according to any one of embodiments 6-23 wherein the    chelator is of the formula:

-   A¹, A², A³ and A⁴ are each N;-   A⁵, A⁶ and A⁸ are each OH;-   A⁷ is a bond to L_(n);-   E¹, E², E³, E⁴ are each independently C₂ alkyl; and-   E⁵, E⁶, E⁷, E⁸ are each independently C₂ alkyl substituted with 0-1    R²³;-   R²³ is ═O.    (25) A compound according to any one of embodiments 6-24 wherein the    chelator is of the formula:

-   A¹ is NR²⁶-   R²⁶ is a co-ordinate bond to a metal or a hydrazine protecting    group;-   E¹ is a bond;-   A² is NHR¹⁹;-   R¹⁹ is a heterocycle substituted with R²³, the heterocycle being    selected from pyridine and pyrimidine;-   R²³ is selected from a bond to the linking group, C(═O)NHR²⁴ and    C(═O)R²⁴; and-   R²⁴ is a bond to the linking group.    (26) A compound according to any one of embodiments 6-25 wherein the    chelator is of the formula:

wherein:

-   A¹ and A³ are each —S(Pg);-   Pg is a thiol protecting group-   E¹ and E⁴ are C₂ alkyl substituted with 0-1 R²³;-   R²³ is ═O;-   A² and A⁴ are each —NH;-   E² is CH₂;-   E³ is C₁₋₃ alkyl substituted with 0-1 R²³;-   A³ is a bond to Ln.    (27) A compound according to any one of embodiments 6-26 wherein the    chelator is of the formula:

wherein:

-   A¹ is a bond to Ln;-   E¹ is C₁ alkyl substituted by R²³;-   A² is NH;-   E² is C₂ alkyl substituted with 0-1R²³;-   A³ is —O—P(O)(R²¹)—O;-   E³ is C₁ alkyl;-   A⁴ and A⁵ are each —O—;-   E⁴ and E⁶ are each independently C₁₋₁₅ alkyl substituted with    0-1R²³;-   E⁵ is C₁ alkyl;-   R²¹ is —OH; and-   R²³ is ═O.    (28) A compound of embodiment 1 having the formula:

(Q)_(d)-L_(n)-C_(h)

wherein, Q is a compound of Formulae (Ia) or (Ib):

wherein,

-   R is independently OH or —CH₂SH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₂₀ alkyl;-   X is independently C═O or SO₂, provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶;

-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, pbenyl    and heterocycle groups are optionally substituted with a bond to    L_(n);-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₃—, optionally substituted with a bond to    L_(n);-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₃)₃—NH—, optionally substituted with a bond to L_(n); or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R⁸ is independently at each occurrence OH or phenyl, optionally    substituted with a bond to L_(n), provided that when R⁸ is phenyl,    R¹⁰ is —C(═O)—CR¹²—NH—CH(CH₃)—COOH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to L_(n), or are taken together with the carbon atom to    which they are attached to form a 5-7 atom saturated, partially    unsaturated or aromatic ring system containing 0-3 heteroatoms    selected from O, N, SO₂ and S, said ring system substituted with R⁶    and optionally substituted with a bond to L_(n);-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to La, or are taken together with the    nitrogen atom to which they are attached to form a 5-7 atom    saturated, partially unsaturated or aromatic ring system containing    0-3 heteroatoms selected from O, N, SO₂ and S, said ring system    optionally substituted with 0-3 R²⁷ or a bond to L_(n);-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system optionally substituted with a bond to    Ln;-   R¹² is independently C₁₋₂₀ alkyl;-   d is selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   L_(n) is a linking group having the formula:

((W¹)_(h)-(CR¹³R¹⁴)_(g))_(x)—(Z)_(k)—((CR^(13a)R^(14a))_(g′)-(W²)_(h′))_(x′);

-   W¹ and W² are independently selected at each occurrence from the    group: O, S, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O),    C(═O)O, OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, SO₂NH, —(OCH₂CH₂)₇₆₋₈₄,    (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t),    and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-3 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-3 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, PO₃H, C₁-C₅ alkyl    substituted with 0-3 R¹⁶, aryl substituted with 0-3 R¹⁶, benzyl    substituted with 0-3 R¹⁶, and C₁-C₅ alkoxy substituted with 0-3 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to    C_(h);-   R¹⁶ is independently selected at each occurrence from the group: a    bond to C_(h), COOR¹⁷, C(═O)NHR¹⁷, NHC(═O)R¹⁷, OH, NHR¹⁷, SO₃H,    PO₃H, —OPO₃H₂, —OSO₃H, aryl substituted with 0-3 R¹⁷, C₁₋₅ alkyl    substituted with 0-1 R¹⁸, C₁₋₅ alkoxy substituted with 0-1 R¹⁸, and    a 5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-3    R¹⁷;-   R¹⁷ is independently selected at each occurrence from the group: H,    alkyl substituted with 0-1 R¹⁸, aryl substituted with 0-1 R¹⁸, a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-1    R¹⁸, C₃₋₁₀ cycloalkyl substituted with 0-1 R¹⁸, polyalkylene glycol    substituted with 0-1 R¹⁸, carbohydrate substituted with 0-1 R¹⁸,    cyclodextrin substituted with 0-1 R¹⁸, amino acid substituted with    0-1 R¹⁸, polycarboxyalkyl substituted with 0-1 R¹⁸, polyazaalkyl    substituted with 0-1 R¹⁸, peptide substituted with 0-1 R¹⁸, wherein    the peptide is comprised of 2-10 amino acids,    3,6-O-disulfo-B-D-galactopyranosyl, bis(phosphonomethyl)glycine, and    a bond to C_(h);-   R¹⁸ is a bond to C_(h);-   k is selected from 0, 1, and 2;-   h is selected from 0, 1, and 2;-   h′ is selected from 0, 1, and 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s″ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 05;-   x is selected from 0, 1, 2, 3, 4, and 5;-   x′ is selected from 0, 1, 2, 3, 4, and 5;-   C_(h) is a metal bonding unit having a formula selected from the    group:

-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: N, NR²⁶, NR¹⁹, NR¹⁹R²⁰, S, SH,    —S(Pg), O, OH, PR¹⁹, PR¹⁹R²⁰, —O—P(O)(R²¹)—O—, P(O)R²¹R²², a bond to    the targeting moiety and a bond to the linking group;-   Pg is a thiol protecting group;-   E¹, E², E³, E⁴, E⁵, E⁶, E⁷, and E⁸ are independently a bond, CH, or    a spacer group independently selected at each occurrence from the    group: C₁-C₁₆ alkyl substituted with 0-3 R²³, aryl substituted with    0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3 R²³,    heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³, wherein the    heterocyclo group is a 5-10 membered heterocyclic ring system    containing 1-4 heteroatoms independently selected from N, S, and O,    C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀    aryl-substituted with 0-3 R²³, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O and substituted with 0-3 R²³;-   R¹⁹ and R²⁰ are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, hydrogen,    C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with 0-3    R²³, C₁₋₁₀ cycloalkyl substituted with 0-3 R²³, heterocyclo-C₁₋₁₀    alkyl substituted with 0-3 R²³, wherein the heterocyclo group is a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl    substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀ aryl-substituted with    0-3 R²³, a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³, and an electron, provided that when one of R¹⁹ or R²⁰    is an electron, then the other is also an electron;-   R²¹ and R²² are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, —OH, C₁-C₁₀    alkyl substituted with 0-3 R²³, C₁-C₁₀ alkyl substituted with 0-3    R²³, aryl substituted with 0-3 R²³, C₃₋₁₀ cycloalkyl substituted    with 0-3 R²³, heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³,    wherein the heterocyclo group is a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀    alkyl-C₆₋₁₀ aryl-substituted with 0-3 R²³, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R²³;-   R²³ is independently selected at each occurrence from the group: a    bond to the linking group, a bond to the targeting moiety, ═O, F,    Cl, Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴, —C(═O)N(R²⁴)₂, —CHO,    —CH₂OR²⁴, —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴, —OC(═O)N(R²⁴)₂,    —NR²⁵C(═O)R²⁴, —NR²⁵C(═O)OR^(24a), —NR²⁵C(═O)N(R²⁴)₂,    —NR²⁵SO₂N(R²⁴)₂, —NR²⁵SO₂R^(24a), —SO₃H, —SO₂R^(24a), —SR²⁴,    —S(═O)R^(24a), —SO₂N(R²⁴)₂, —N(R²⁴)₂, —NHC(═S)NHR²⁴, ═NOR²⁴, NO₂,    —C(═O)NHOR²⁴, —C(═O)NHNR²⁴R^(24a), —OCH₂CO₂H,    2-(1-morpholino)ethoxy, C₁-C₅ alkyl, C₂-C₄ alkenyl, C₃-C₆    cycloalkyl, C₃-C₆ cycloalkylmethyl, C₂-C₆ alkoxyalkyl, aryl    substituted with 0-2 R²⁴, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O; and-   wherein at least one of A¹, A², A³, A⁴, A⁵, A⁶, A⁷, A⁸ or R²³ is a    bond to the linking group or targeting moiety;-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to the linking group, a bond to the targeting    moiety, H, C₁-C₆ alkyl, phenyl, benzyl, C₁-C₆ alkoxy, halide, nitro,    cyano, and trifluoromethyl; and-   R²⁶ is a co-ordinate bond to a metal or a hydrazine protecting    group; or-   a pharmaceutically acceptable salt thereof.    (29) A compound according to embodiment 28 wherein:-   R is —OH;-   R² is C₁₋₆ alkyl;-   X is C═O:-   R³ is

-   R¹ and R⁴ are taken together to form a bridging group of formula    —(CH₂)₃—O-phenyl-CH₂—;-   R⁵ is NH(C₁₋₆alkyl), substituted with a bond to the linking group or    a bond to the chelator.    (30) A compound according to any one of embodiments 28-29 wherein-   R is —OH;-   R⁹ is C₁ alkyl substituted with a bond to Ln;-   R¹⁰ and R¹¹ taken together with the nitrogen atom to which they are    attached form a 5 atom saturated ring system, said right system is    substituted with 0-3 R²⁷;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸; and-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups.    (31) A compound according to any one of embodiments 28-30 wherein-   R is —OH;-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅-7 atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (32) A compound according to any one of embodiments 28-31 wherein-   d is selected from 1, 2, 3, 4, and 5;-   W is independently selected at each occurrence from the group: O,    NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O), C(═O)O, OC(═O),    NHC(═S)NH, NHC(═O)NH, SO₂, (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′),    (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t), and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-1 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-1 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-1 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, C₁-C₅ alkyl    substituted with 0-1 R¹⁶, aryl substituted with 0-1 R¹⁶, benzyl    substituted with 0-1 R¹⁶, and C₁-C₅ alkoxy substituted with 0-1 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to    C_(h);-   k is 0 or 1;-   s is selected from 0, 1, 2, 3, 4, and 5;-   s′ is selected from 0, 1, 2, 3, 4, and 5;-   s″ is selected from 0, 1, 2, 3, 4, and 5;-   t is selected from 0, 1, 2, 3, 4, and 5;-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: NR¹⁹, NR¹⁹R²⁰, S, SH, OH, and a bond    to L_(n);-   E is a bond, CH, or a spacer group independently selected at each    occurrence from the group: C₁-C₁₀ alkyl substituted with 0-3 R²³,    aryl substituted with 0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3    R²³, and a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³;-   R¹⁹, and R²⁰ are each independently selected from the group: a bond    to Ln, hydrogen, C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl    substituted with 0-3 R²³, a 5-10 membered heterocyclic ring system    containing 1-4 heteroatoms independently selected from N, S, and O    and substituted with 0-3 R²³, and an electron, provided that when    one of R¹⁹ or R²⁰ is an electron, then the other is also an    electron;-   R²³ is independently selected at each occurrence from the group; a    bond to L_(n), ═O, F, Cl, Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴,    —C(═O)N(R²⁴)₂, —CH₂OR²⁴, —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴,    —OC(═O)N(R²⁴)₂, —NR²⁵C(═O)R²⁴, —NR²⁵C(═O)OR^(24a),    —NR²⁵C(═O)N(R²⁴)₂, —NR²⁵SO₂N(R²⁴)₂, —NR²⁵SO₂R^(24a), —SO₃H,    —SO₂R^(24a), —S(═O)R^(24a), —SO₂N(R²⁴)₂, —N(R²⁴)₂, —NHC(═S)NHR²⁴,    ═NOR¹⁸, —C(═O)NHNR¹⁸R^(18a), —OCH₂CO₂H, and 2-(1-morpholino)ethoxy;    and-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to L_(n), H, and C₁-C₆ alkyl; and    (33) A compound according to any one of embodiments 28-32 wherein-   d is 1,-   C_(h) is

-   A¹ is a bond to L_(n);-   A², A⁴, and A⁶ are each N;-   A³, A⁵, A⁷ and A⁸ are each OH;-   E¹, E², and E⁴ are C2 alkyl;-   E³, E⁵, E⁷, and E⁸ are C₂ alkyl substituted with 0-1 R²³;-   R²³ is ═O;    (34) A compound according to any one of embodiments 28-33 wherein-   C_(h) is

wherein:

-   A5 is a bond to Ln;-   A¹, A³, A⁷ and A⁸ are each OH;-   A², A⁴ and A⁶ are each NH;-   E¹, E³, E⁵, E⁷, and E⁸ are C₂ alkyl substituted with 0-1 R²³;-   E², and E⁴, are C₂ alkyl;-   R²³ is ═O.    (35) A coepound according to any one of embodiments 28-34 is wherein-   C_(h) is

-   A¹, A², A³ and A⁴ are each N;-   A⁵, A⁶ and A⁸ are each OH:-   A⁷ is a bond to L_(n);-   E¹, E², E³, E⁴ are each independently, C₂ alkyl; and-   E⁵, E⁶, E⁷, E⁸ are each independently, C₂ alkyl substituted with 0-1    R²³;-   R²³ is ═O;    (36) A compound according to any one of embodiments 28-35 wherein-   C_(h) is

-   A¹ is NR²⁶;-   R²⁶ is a co-ordinate bond to a metal; or a hydrazine protecting    group;-   E¹ is a bond;-   A² is NHR¹⁹;-   R¹⁹ is a heterocycle substituted with R²³, the heterocycle being    selected from pyridine and pyrimidine;-   R²³ is selected from a bond to L_(n), C(═O)NHR²⁴ and C(═O)R²⁴; and-   R²⁴ is a bond to L_(n).    (37) A compound according to any one of embodiments 28-36 wherein

wherein:

-   A¹ and A⁵ are each —S(Pg);-   Pg is a thiol protecting group;-   E¹ and E⁴ are C₂ alkyl substituted with 0-1 R²³;-   R²³ is ═O;-   A² and A⁴ are each —NH;-   E² is CH₂;-   E³ is C1-3 alkyl substituted with 0-1 R²³;-   A³ is a bond to Ln.    (38) A compound according to any one of embodiments 28-37 wherein

wherein

-   A¹ is a bond to Ln;-   E¹ is C₁ alkyl substituted by R²³;-   A² is NH;-   E² is C₂ alkyl substituted with 0-1R²³;-   A³ is —O—P(O)(R²¹)—O;-   E³ is C₁ alkyl;-   A⁴ and A⁵ are each —O—;-   E⁴ and E⁶ are each independently C₁₋₁₆ alkyl substituted with    0-1R²³;-   E⁵ is C₁ alkyl;-   A⁵ is —O—-   R²¹ is —OH; and-   R²³ is ═O.    (39) A compound according embodiment 28 wherein-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0:-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (40) A compound according to embodiments 28 wherein-   x is 0;-   k is 1;-   Z is aryl substituted with 0-3 R¹⁶;-   g′ is 1;-   W² is NH;-   R^(13a) and R^(14a) are independently H;-   h′ is 1; and-   x′ is 1.    (41) A compound according to embodiments 28 wherein-   W¹ is C(O)NR¹⁵;-   h is 1;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 1;-   R^(13a) and R^(14a) are independently H; or C1-5 alkyl substituted-   with 0-3 R¹⁶;-   R¹⁶ is SO₃H;-   W² is NHC(═O) or NH;-   h′ is 1; and-   x′ is 2.    (42) A compound according to embodiment 28 wherein-   W¹ is C(═O)NH;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   x is 1;-   W² is —NH(C═O)— or —(OCH₂CH₂)₇₆₋₈₄—;-   h′ is 2; and-   x′ is 1.    (43) A compound according to embodiment 28 wherein-   x is 0;-   k is 0;-   g′ is 3;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (44) A compound according to embodiment 28 wherein-   x is 0;-   Z is aryl substituted with 0-3 R¹⁶;-   k is 1;-   g′ is 1;-   R^(13a)R^(14a) are independently H;-   W² is NHC(═O) or —(OCH2CH2)₇₆₋₈₄—; and-   x′ is 1.    (45) A compound according to embodiment 28 wherein-   W¹ is C═O;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (46) A compound according to embodiment 1 or 28 selected from the    group consisting of:-   2-{[5-(3-{2-[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-acetylamino}-propylcarbamoyl)-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonic    acid;-   2-{[5-(4-{[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-10-carbonyl)-amino]-methyl)-benzylcarbamoyl}-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonic    acid;-   2-[7-({N-[3-(2-{[7-(N-hydroxycabamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]carbamoyl}methyl)-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl]acetic    acid,-   2-{7-[(N-{(4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-carbonylamino{methyl)phenyl]methyl}carbamoyl)methyl]-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl}acetic    acid;-   2-(7-{[N-(1-{N-[3-(2-([7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1    (15),12(16),13-trien-3-yl]carbonylamino)acetylamino)propyl]carbamoyl}-2-sulfoethyl)carbamoyl]methyl}-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl)acetic    acid;-   2-[7-({N-[1-(N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12    (16),13-trien-3-yl]-carbonylamino}methyl)phenyl]methyl}carbamoyl)-2-sulfoethyl]carbamoyl}methyl)-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl]acetic    acid;-   2-({2-[({N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]carbamoyl}methyl)(carboxymethyl)amino}ethyl){2-[bis(carboxymethyl)amino]ethyl}amino]acetic    acid;-   2-[(2-{[(N-{4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-carbonylamino}methyl)phenyl]methyl}carbamoyl)methyl](carboxymethyl)amino}ethyl){2-[bis(carboxymethyl)amino]ethyl}amino]acetic    acid;-   N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]-4,5-bis[2-(ethoxyethylthio)acetylamino]pentanamide;-   N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl)carbonylamino}methyl)-phenyl]methyl}-4,5-bis[2-(ethoxyethylthio)acetylamino]-pentanamide;-   1-(1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamino)-α,ω-dicarbonylPEG₃₄₀₀-2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}-N-(3-aminopropyl)acetamide;-   1-(1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamino)-α,ω-dicarbonylPEG₃₄₀₀-[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-N-{[4-(aminomethyl)phenyl]methyl}carboxamide    conjugate;-   2-[2-({5-[N-(5-(N-hydroxycarbamoyl)(5R)-5-{3-[4-(3,4-dimethoxyphenoxy)phenyl]-3-methyl-2-oxopyrrolidinyl}pentyl)carbamoyl](2-pyridyl)}amino)(1Z)-2-azavinyl]benzenesulfonic    acid;-   2-(2-{[5-(N-{3-[3-(N-hydroxycarbamoyl)(4S)-4-({4-[(4-methylphenyl)methoxy]piperidyl}carbonyl)piperidyl]-3-oxopropyl}carbamoyl)(2-pyridyl)]amino}(1Z)-2-azavinyl)benzenesulfonic    acid; and

(47) In some embodiments, a radiopharmaceutical comprising a compound ofany one of embodiments 1-46 and a cytotoxic radioisotope which iscomplexed to the chelator.(48) In some embodiments, a radiopharmaceutical comprising a compound ofany one of embodiments 1-47 and a cytotoxic radioisotope which iscomplexed to the chelator.(49) In some embodiments, a radiopharmaceutical comprising a compound ofany one of embodiments 1-47 and a cytotoxic radioisotope.(50) In some embodiments, a radiopharmaceutical according to embodiment20 selected from the group consisting of:2-{[5-(3-{2-[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.-2.2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-acetylamino}-propy-lcarbamoyl)-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonicacid; and2-{[5-(4-{[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.-2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-methyl}-benzylcarbam-oyl)-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonicacid; wherein the cytotoxic radioisotope is ^(99m)Tc.(51) In some embodiments, a radiopharmaceutical according to embodiment47 wherein the cytotoxic radioisotope is selected from the groupconsisting of beta particle emitters, alpha particle emitters, and Augerelectron emitters.(52) In some embodiments, a radiopharmaceutical according to embodiment47 wherein the cytotoxic radioisotope is selected from the groupconsisting of: ¹⁸⁶Re, ¹⁸⁸Re, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁴⁹Pm, ⁹⁰Y, ²¹²Bi,¹⁰³Pd, ¹⁰⁹Pd, ¹⁵⁹Gd, ¹⁴⁰La, ¹⁹⁸Au, ¹⁹⁹Au, ₁₆₉Yb, .sup.¹⁷⁵Yb, ¹⁶⁵Dy,¹⁶⁶Dy, ⁶⁷Cu, ¹⁰⁵Rh, ¹¹¹Ag, and ¹⁹²Ir.(53) In some embodiments, a radiopharmaceutical according to embodiment47 wherein the cytotoxic radioisotope is selected from the groupconsisting of: ¹⁸⁶Re, ¹⁸⁸Re, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁴⁹Pm, ⁹⁰Y, ²¹²Bi,¹⁰³Pd, ¹⁰⁵Rh,(54) In some embodiments, a radiopharmaceutical according to embodiment47 wherein the cytotoxic radioisotope is selected from the groupconsisting of: ¹⁸⁶Re, ¹⁸⁸Re, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁴⁹Pm, ⁹⁰Y, and ²¹²Bi.(55) In some embodiments, a composition comprising a compound of any oneof embodiments 1-54, or a pharmaceutically acceptable salt thereof, anda pharmaceutically acceptable carrier.b. Second Non-Limiting Set of Embodiments of Imaging Agents orPrecursors Thereof

This section provides non-limiting embodiments of compounds which mayfunction as imaging agents and/or imaging agent precursors (alsoreferred to herein as a diagnostic agent). In some embodiments, acompound is provided, wherein the compounds may be associated with aradioisotope, thereby forming an imaging agent (or diagnostic agent).

(1) In some embodiments, the diagnostic agent (or imaging agent) is ofembodiment 1 of this second non-limiting set of embodiments, wherein thediagnostic agent (or imaging agent) comprises:

-   i) 1-10 targeting moieties;-   ii) a chelator; and-   iii) 0-1 linking groups between the targeting moiety and chelator;    wherein the targeting moiety is a matrix metalloproteinase    inhibitor; and    wherein the chelator is capable of conjugating to the diagnostic    metal.    (2) A diagnostic agent according to embodiment 1, wherein the    targeting moiety is a matrix metalloproteinase inhibitor having an    inhibitory constant K_(i) of <1000 nM.    (3) A diagnostic agent according to any of embodiments 1-2, wherein    the targeting moiety is a matrix metalloproteinase inhibitor having    an inhibitory constant K_(i) of <100 nM.    (4) A diagnostic agent according to any of embodiments 1-3,    comprising 1-5 targeting moieties.    (5). A diagnostic agent according to any of embodiments 1-4,    comprising one targeting moiety.    (6) A diagnostic agent any of embodiments 1-5, wherein the targeting    moiety is an inhibitor of one or more matrix metalloproteinases    selected from the group consisting of MMP-1, MMP-2, MMP-3, MMP-9,    and MMP-14.    (7) A diagnostic agent of any one of embodiments 1-6, wherein the    targeting moiety is an inhibitor of one or more matrix    metalloproteinases selected from the group consisting of MMP-2,    MMP-9, and MMP-14.    (8) A diagnostic agent according to any one of embodiments 1-7    wherein the targeting moiety is a matrix metalloproteinase inhibitor    of the formulae (Ia) or (Ib):

wherein,

-   R is independently OH or —CH₃SH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₂₀ alkyl;-   X is independently C═O or SO₂, provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶;

-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to the    linking group or a bond to the chelator;-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with as bond    to the linking group or a bond to the chelator;-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to the    linking group or a bond to the chelator; or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R⁸ is independently at each occurrence OH or phenyl, optionally    substituted with a bond to the linking group or a bond to the    chelator, provided that when R⁸ is phenyl, R¹⁰ is    —C(═O)—CR¹²—NH—CH(CH₃)—COOH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to the linking group or a bond to the chelator, or are    taken together with the carbon atom to which R⁹ and R^(9′) are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system substituted with R⁶ and optionally    substituted with a bond to the linking group or a bond to the    chelator;-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to the linking group or a bond to the    chelator, or are taken together with the nitrogen atom to which they    are attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system optionally substituted with 0-3 R²⁷, a    bond to the linking group or a bond to the chelator;-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂, and S, said ring system optionally substituted with a bond to    the linking group or a bond to the chelator; and-   R¹² is independently C₁₋₂₀ alkyl;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸;-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (9). A diagnostic agent according to any one of embodiments 1-8    wherein the targeting moiety is a matrix metalloproteinase inhibitor    of the formulae (Ia) or (Ib):

wherein,

-   R is OH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₆ alkyl;-   X is C═O;-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to the    linking group or a bond to the chelator;-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with a bond to    the linking group or a bond to the chelator;-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to the    linking group or a bond to the chelator; or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R⁸ is OH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to the linking group or a bond to the chelator, or are    taken together with the carbon atom to which R⁹ and R^(9′) are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with a bond to the linking    group or a bond to the chelator;-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to the linking group or a bond to the    chelator, or are taken together with the nitrogen atom to which they    are attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with 0-3 R²⁷, a bond to the    linking group or a bond to the chelator;-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with a bond to the linking    group or a bond to the chelator; and-   R¹² is independently C₁₋₆ alkyl;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸;-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (10). A diagnostic agent according to any one of embodiments 1-9    wherein the targeting moiety is a matrix metalloproteinase inhibitor    of the formulae (Ia) or (Ib):    wherein:-   R is —OH;-   R² is C₁₋₆ alkyl;-   X is C═O;-   R³ is

-   R¹ and R⁴ are taken together to form a bridging group of formula    —(CH₂)₃—O-phenyl-CH₂—;-   R⁵ is NH(C1-6alkyl), substituted with a bond to the linking group or    a bond to the chelator.    (11) A diagnostic agent according to any one of embodiments 1-10,    wherein:

R is —OH;

R⁹ is C₁ alkyl substituted with a bond to Ln;R¹⁰ and R¹¹ taken together with the nitrogen atom to which they areattached form a 5 atom saturated ring system, said right system issubstituted with 0-3 R²⁷;R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸; andR²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups.(12) A diagnostic agent according to any one of embodiments 1-11 whereinthe

R is —OH;

R¹ and R² taken together with the nitrogen and carbon atom through whichthey are attached form a C₅₋₇ atom saturated ring system substitutedwith one or more substituents selected from the group consisting of: abond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;R²⁹ and R³⁰ taken together with the nitrogen atom through which they areattached form a C5-7 atom saturated ring system substituted with R³¹;andR³¹ is a benzyloxy group substituted with C1-4 alkyl.(13) A diagnostic agent according to any one of embodiments 1-12 whereinthe linking group is of the formula:

((W¹)_(h)-(CR¹³R¹⁴)_(g))_(x)—(Z)_(k)—((CR^(13a)R^(14a))_(g′)-(W²)_(h′))_(x′);

-   W¹ and W² are independently selected at each occurrence from the    group: O, S, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O),    C(═O)O, OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, SO₂NH, —(OCH₂CH₂)₇₆₋₈₄,    (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t),    and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-3 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-3 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, PO₃H, C₁-C₅ alkyl    substituted with 0-3 R¹⁶, aryl substituted with 0-3 R¹⁶, benzyl    substituted with 0-3 R¹⁶, and C₁-C₅ alkoxy substituted with 0-3 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to the    chelator;-   R¹⁶ is independently selected at each occurrence from the group: a    bond to the chelator, COOR¹⁷, C(═O)NHR¹⁷, NHC(═O)R¹⁷, OH, NHR¹⁷,    SO₃H, PO₃H, —OPO₃H₂, —OSO₃H, aryl substituted with 0-3 R¹⁷, C₁₋₅    alkyl substituted with 0-1 R¹⁸, C₁₋₅ alkoxy substituted with 0-1    R¹⁸, and a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R¹⁷;-   R¹⁷ is independently selected at each occurrence from the group: H,    alkyl substituted with 0-1 R¹⁸, aryl substituted with 0-1 R¹⁸, a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-1    R¹⁸, C₃₋₁₀ cycloalkyl substituted with 0-1 R¹⁸, polyalkylene glycol    substituted with 0-1 R¹⁸, carbohydrate substituted with 0-1 R¹⁸,    cyclodextrin substituted with 0-1 R¹⁸, amino acid substituted with    0-1 R¹⁸, polycarboxyalkyl substituted with 0-1 R¹⁸, polyazaalkyl    substituted with 0-1 R¹⁸, peptide substituted with 0-1 R¹⁸, wherein    the peptide is comprised of 2-10 amino acids,    3,6-O-disulfo-B-D-galactopyranosyl, bis(phosphonomethyl)glycine, and    a bond to the chelator;-   R¹⁸ is a bond to the chelator;-   k is selected from 0, 1, and 2;-   h is selected from 0, 1, and 2;-   h′ is selected from 0, 1, and 2;-   g is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s″ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   x is selected from 0, 1, 2, 3, 4, and 5; and-   x′ is selected from 0, 1, 2, 3, 4, and 5.    (14) A diagnostic agent according to any one of embodiments 1-13    wherein-   W¹ and W² are independently selected at each occurrence from the    group: O, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O), C(═O)O,    OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, —(CH₂CH₂O)₇₆₋₈₄—, (OCH₂CH₂)_(s),    (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t), and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-1 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-1 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-1 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, C₁-C₅ alkyl    substituted with 0-1 R¹⁶, aryl substituted with 0-1 R¹⁶, benzyl    substituted with 0-1 R¹⁶, and C₁-C₅ alkoxy substituted with 0-1 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to the    chelator;-   k is 0 or 1;-   s is selected from 0, 1, 2, 3, 4, and 5;-   s′ is selected from 0, 1, 2, 3, 4, and 5;-   s″ is selected from 0, 1, 2, 3, 4, and 5; and-   t is selected from 0, 1, 2, 3, 4, and 5.    (15) A diagnostic agent according to embodiment 13 wherein wherein:-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 0:-   h′ is 1;-   W² is NH; and-   x′ is 1.    (16) A diagnostic agent according to embodiment 13 wherein-   x is 0;-   k is 1;-   Z is aryl substituted with 0-3 R¹⁶;-   g′ is 1;-   W² is NH;-   R^(13a) and R^(14a) are independently H;-   h′ is 1; and-   x′ is 1.    (17) A diagnostic agent according to embodiment 13 wherein-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 1;-   R^(13a) and R^(14a) are independently H; or C1-5 alkyl substituted-   with 0-3 R¹⁶;-   R¹⁶ is SO₃H;-   W² is NHC(═O) or NH;-   h′ is 1; and-   x′ is 2.    (18). A diagnostic agent according to embodiment 13 wherein-   W¹ is C(O)NH;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   x is 1;-   W² is —NH(C═O)— or —(OCH₂CH₂)₇₆₋₈₄—;-   h′ is 2; and-   x′ is 1.    (19) A diagnostic agent according to embodiment 13 wherein-   x is 0;-   k is 0;-   g′ is 3;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (20) A diagnostic agent according to embodiment 13 wherein-   x is 0;-   Z is aryl substituted with 0-3 R¹⁶,-   k is 1;-   g′ is 1;-   R^(13a)R^(14a) are independently H;-   W² is NHC(═O) or —(OCH2CH2)₇₆₋₈₄-; and-   x′ is 1.    (21) A diagnostic agent according to embodiment 13 wherein-   W¹ is C═O;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (22) A compound according to embodiment 1 wherein the linking group    is absent.    (23) A diagnostic agent according to any one of embodiments 1-22    wherein the chelator is a metal bonding unit having a formula    selected from the group:

-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: N, NR²⁶, NR¹⁹, NR¹⁹R²⁰, S, SH,    —S(Pg), O, OH, PR¹⁹, PR¹⁹R²⁰, —O—P(O)(R²¹)—O—, P(O)R²¹R²², a bond to    the targeting moiety and a bond to the linking group;-   Pg is a thiol protecting group;-   E¹, E², E³, E⁴, E⁵, E⁶, E⁷, and E⁸ are independently a bond, CH, or    a spacer group independently selected at each occurrence from the    group: C₁-C₁₆ alkyl substituted with 0-3 R²³, aryl substituted with    0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3 R²³,    heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³, wherein the    heterocyclo group is a 5-10 membered heterocyclic ring system    containing 1-4 heteroatoms independently selected from N, S, and O,    C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀    aryl-substituted with 0-3 R²³, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O and substituted with 0-3 R²³;-   R¹⁹ and R²⁰ are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, hydrogen,    C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with 0-3    R²³, C₁₋₁₀ cycloalkyl substituted with 0-3 R²³, heterocyclo-C₁₋₁₀    alkyl substituted with 0-3 R²³, wherein the heterocyclo group is a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl    substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀ aryl-substituted with    0-3 R²³, a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³, and an electron, provided that when one of R¹⁹ or R²⁰    is an electron, then the other is also an electron;-   R²¹ and R²² are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, —OH, C₁-C₁₀    alkyl substituted with 0-3 R²³, C₁-C₁₀ alkyl substituted with 0-3    R²³, aryl substituted with 0-3 R²³, C₃₋₁₀ cycloalkyl substituted    with 0-3 R²³, heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³,    wherein the heterocyclo group is a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀    alkyl-C₆₋₁₀ aryl-substituted with 0-3 R²³, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R²³-   R²³ is independently selected at each occurrence from the group: a    bond to the linking group, a bond to the targeting moiety, ═O, F,    Cl, Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴, —C(═O)N(R²⁴)₂, —CHO,    —CH₂OR²⁴, —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴, —OC(═O)N(R²⁴)₂,    —NR²⁵C(═O)R²⁴, —NR²⁵C(═O)OR^(24a), —NR²⁵C(═O)N(R²⁴)₂,    —NR²⁵SO₂N(R²⁴)₂, —NR²⁵SO₂R^(24a), —SO₃H, —SO₂R^(24a), —SR²⁴,    —S(═O)R^(24a), —SO₂N(R²⁴)₂, —N(R²⁴)₂, —NHC(═S)NHR²⁴, ═NOR²⁴, NO₂,    —C(═O)NHOR²⁴, —C(═O)NHNR²⁴R^(24a), —OCH₂CO₂H,    2-(1-morpholino)ethoxy, C₁-C₅ alkyl, C₂-C₄ alkenyl, C₃-C₆    cycloalkyl, C₃-C₆ cycloalkylmethyl, C₂-C₆ alkoxyalkyl, aryl    substituted with 0-2 R²⁴, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O; and-   wherein at least one of A¹, A², A³, A⁴, A⁵, A⁶, A⁷, A⁸ or R²³ is a    bond to the linking group or targeting moiety;-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to the linking group, a bond to the targeting    moiety, H, C₁-C₆ alkyl, phenyl, benzyl, C₁-C₆ alkoxy, halide, nitro,    cyano, and trifluoromethyl; and-   R²⁶ is a co-ordinate bond to a metal or a hydrazine protecting    group; or a pharmaceutically acceptable salt thereof.    (24) A diagnostic agent according to any one of embodiments 1-23    wherein:-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: NR¹⁹, NR¹⁹R²⁰, S, SH, OH, a bond to    the targeting moiety and a bond to the linking group;-   E¹, E², E³, E⁴, E⁵, E⁶, E⁷, and E⁸ are independently a bond, CH, or    a spacer group independently selected at each occurrence from the    group: C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with    0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3 R²³, and a 5-10    membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-3    R²³;-   wherein at least one of A¹, A², A³, A⁴, A⁵, A⁶, A⁷, A⁸ and R²³ is a    bond to the linking group or the targeting moiety;-   R¹⁹, and R²⁰ are each independently selected from the group: a bond    to the targeting moiety, a bond to the linking group, hydrogen,    C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with 0-3    R²³, a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³, and an electron, provided that when one of R¹⁹ or R²⁰    is an electron, then the other is also an electron;-   R²³ is independently selected at each occurrence from the group: a    bond to the targeting moiety, a bond to the linking group, ═O, F,    Cl, Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴, —C(═O)N(R²⁴)₂, —CH₂OR²⁴,    —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴, —OC(═O)N(R²⁴)₂, —NR²⁵C(═O)R²⁴,    —NR²⁵C(═O)OR^(24a), —NR²⁵C(═O)N(R²⁴)₂, —NR²⁵SO₂N(R²⁴)₂,    —NR²⁵SO₂R^(24a), —SO₃H, —SO₂R^(24a), —S(═O)R^(24a), —SO₂N(R²⁴)₂,    —N(R²⁴)₂, —NHC(═S)NHR²⁴, ═NOR¹⁸, —C(═O)NHNR¹⁸R^(18a), —OCH₂CO₂H, and    2-(1-morpholino)ethoxy; and-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to the linking group, H, and C₁-C₆ alkyl.    (25) A diagnostic agent according to any one of embodiments 1-24    wherein the chelator is of the formula:

-   A¹ is a bond to the linking group;-   A², A⁴, and A⁶ are each N;-   A³, A⁵, A⁷ and A⁸ are each OH;-   E¹, E², and E⁴ are C2 alkyl;-   E³, E⁵, E⁷, and E⁸ are C₂ alkyl substituted with 0-1 R²³;-   R²³ is ═O.    (26) A diagnostic agent according to any one of embodiments 1-25    wherein the chelator is of the formula:-   C_(h) is

wherein:

-   A5 is a bond to Ln;-   A¹, A³, A⁷ and A⁸ are each OH;-   A², A⁴ and A⁶ are each NH;-   E¹, E³, E⁵, E⁷, and E⁸ are C₂ alkyl substituted with 0-1 R²³;-   E², and E⁴, are C₂ alkyl;-   R²³ is ═O.    (27) A diagnostic agent according to any one of embodiments 1-26    wherein the chelator is of the formula:

-   A¹, A², A³ and A⁴ are each N;-   A⁵, A⁶ and A⁸ are each OH;-   A⁷ is a bond to L_(n);-   E¹, E², E³, E⁴ are each independently C₂ alkyl; and-   E⁵, E⁶, E⁷, E⁸ are each independently C₂ alkyl substituted with 0-1    R²³;-   R²³ is ═O.    (28) A diagnostic agent according to any one of embodiments 1-27    wherein the chelator is of the formula:

-   A¹ is NR²⁶;-   R²⁶ is a co-ordinate bond to a metal or a hydrazine protecting    group;-   E¹ is a bond;-   A² is NHR¹⁹;-   R¹⁹ is a heterocycle substituted with R²³, the heterocycle being    selected from pyridine and pyrimidine;-   R²³ is selected from a bond to the linking group, C(═O)NHR²⁴ and    C(═O)R²⁴; and-   R²⁴ is a bond to the linking group.    (29) A diagnostic agent according to any one of embodiments 1-28    wherein the chelator is of the formula:

wherein:

-   A¹ and A⁵ are each —S(Pg);-   Pg is a thiol protecting group;-   E¹ and E⁴ are C₂ alkyl substituted with 0-1 R²³;-   R²³ is ═O;-   A² and A⁴ are each —NH;-   E² is CH₂;-   E³ is C₁₋₃ alkyl substituted with 0-1 R²³;-   A³ is a bond to Ln.    (30) A diagnostic agent according to any one of embodiments 1-29    wherein the chelator is of the formula:

wherein:

-   A¹ is a bond to Ln;-   E¹ is C₁ alkyl substituted by R²³;-   A² is NH;-   E² is C₂ alkyl substituted with 0-1R²³;-   A³ is —O—P(O)(R²¹)—O;-   E³ is C₁ alkyl;-   A⁴ and A⁵ are each —O—;-   E⁴ and E⁶ are each independently C₁₋₁₆ alkyl substituted with    0-1R²³;-   E⁵ is C₁ alkyl;-   R²¹ is —OH; and-   R²³ is ═O.    (31) A diagnostic agent according to embodiment 1 having the    formula:

(Q)_(d)-L_(n)-C_(h)

wherein, Q is a compound of Formulae (Ia) or (Ib):

wherein,

-   R is independently OH or —CH₂SH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₂₀ alkyl;-   X is independently C═O or SO₂, provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶;

-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to    L_(n);-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH)₃—O-phenyl-CH₂—, optionally substituted with a bond to    L_(n);-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to L_(n); or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Ch, and —C(═O)—NR²⁹R³⁰;-   R⁸ is independently at each occurrence OH or phenyl, optionally    substituted with a bond to L_(n), provided that when R⁸ is phenyl,    R¹⁰ is —C(═O)—CR¹²—NH—CH(CH₃)—COOH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to L_(n), or are taken together with the carbon atom to    which they are attached to form a 5-7 atom saturated, partially    unsaturated or aromatic ring system containing 0-3 heteroatoms    selected from O, N, SO₂, and S, said ring system substituted with R⁶    and optionally substituted with a bond to L_(n);-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to L_(n), or are taken together with the    nitrogen atom to which they are attached to form a 5-7 atom    saturated, partially unsaturated or aromatic ring system containing    0-3 heteroatoms selected from O, N, SO₂ and S, said ring system    optionally substituted with 0-3 R²⁷ or a bond to L_(n);-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system optionally substituted with a bond to    L_(n);-   R¹² is independently C₁₋₂₀ alkyl;-   d is selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   L_(n) is a linking group having the formula:

((W¹)_(h)-(CR¹³R¹⁴)_(g))_(x)—(Z)_(k)—((CR^(13a)R^(14a))_(g′)-(W²)_(h′))_(x′);

-   W¹ and W² are independently selected at each occurrence from the    group: O, S, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O),    C(═O)O, OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, SO₂NH, —(OCH₂CH₂)₇₆₋₈₄,    (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t),    and (aa)_(t′),-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-3 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-3 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, PO₃H, C₁-C₅ alkyl    substituted with 0-3 R¹⁶, aryl substituted with 0-3 R¹⁶, benzyl    substituted with 0-3 R¹⁶, and C₁-C₅ alkoxy substituted with 0-3 R¹⁶,    NHC(═O)R¹⁷, C(═O)NR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to    C_(h);-   R¹⁶ is independently selected at each occurrence from the group: a    bond to C_(h), COOR¹⁷, C(═O)NHR¹⁷, NHC(═O)R¹⁷, OH, NHR¹⁷, SO₃H,    PO₃H, —OPO₃H₂, —OSO₃H, aryl substituted with 0-3 R¹⁷, C₁₋₅ alkyl    substituted with 0-1 R¹⁸, C₁₋₅ alkoxy substituted with 0-1 R¹⁸, and    a 5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-3    R¹⁷;-   R¹⁷ is independently selected at each occurrence from the group: H,    alkyl substituted with 0-1 R¹⁸, aryl substituted with 0-1 R¹⁸, a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-1    R¹⁸, C₃₋₁₀ cycloalkyl substituted with 0-1 R¹⁸, polyalkylene glycol    substituted with 0-1 R¹⁸, carbohydrate substituted with 0-1 R¹⁸,    cyclodextrin substituted with 0-1 R¹⁸, amino acid substituted with    0-1 R¹⁸, polycarboxyalkyl substituted with 0-1 R¹⁸, polyazaalkyl    substituted with 0-1 R¹⁸, peptide substituted with 0-1 R¹⁸, wherein    the peptide is comprised of 2-10 amino acids,    3,6-O-disulfo-B-D-galactopyranosyl, bis(phosphonomethyl)glycine, and    a bond to C_(h);-   R¹⁸ is a bond to C_(h);-   k is selected from 0, 1, and 2;-   h is selected from 0, 1, and 2;-   h′ is selected from 0, 1, and 2;-   g is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s″ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   x is selected from 0, 1, 2, 3, 4, and 5;-   x′ is selected from 0, 1, 2, 3, 4, and 5;-   C_(h) is a metal bonding unit having a formula selected from the    group:

-   A¹, A², A³, A⁴, A⁵, A⁶, A⁷, and A⁸ are independently selected at    each occurrence from the group: N, NR²⁶, NR¹⁹, NR¹⁹R²⁰, S, SH,    —S(Pg), O, OH, PR¹⁹, PR¹⁹R²⁰, —O—P(O)(R²¹)—O—, P(O)R²¹R²², a bond to    the targeting moiety and a bond to the linking group;-   Pg is a thiol protecting group;-   E¹, E², E³, E⁴, E⁵, E⁶, E⁷, and E⁸ are independently a bond, CH, or    a spacer group independently selected at each occurrence from the    group: C₁-C₁₆ alkyl substituted with 0-3 R²³, aryl substituted with    0-3 R²³, C₃₋₁₀ cycloalkyl substituted with 0-3 R²³,    heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³, wherein the    heterocyclo group is a 5-10 membered heterocyclic ring system    containing 1-4 heteroatoms independently selected from N, S, and O,    C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀    aryl-substituted with 0-3 R²³, and a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O and substituted with 0-3 R²³;-   R¹⁹ and R²⁰ are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, hydrogen,    C₁-C₁₀ alkyl substituted with 0-3 R²³, aryl substituted with 0-3    R²³, C₁₋₁₀ cycloalkyl substituted with 0-3 R²³, heterocyclo-C₁₋₁₀    alkyl substituted with 0-3 R²³, wherein the heterocyclo group is a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl    substituted with 0-3 R²³, C₁₋₁₀ alkyl-C₆₋₁₀ aryl-substituted with    0-3 R²³, a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R²³, and an electron, provided that when one of R¹⁹ or R²⁰    is an electron, then the other is also an electron;-   R²¹ and R²² are each independently selected from the group: a bond    to the linking group, a bond to the targeting moiety, —OH, C₁-C₁₀    alkyl substituted with 0-3 R²³, C₁-C₁₀ alkyl substituted with 0-3    R²³, aryl substituted with 0-3 R²³, C₃₋₁₀ cycloalkyl substituted    with 0-3 R²³, heterocyclo-C₁₋₁₀ alkyl substituted with 0-3 R²³,    wherein the heterocyclo group is a 5-10 membered heterocyclic ring    system containing 1-4 heteroatoms independently selected from N, S,    and O, C₆₋₁₀ aryl-C₁₋₁₀ alkyl substituted with 0-3 R²³, C₁₋₁₀    alkyl-C₆₋₁₀ aryl-substituted with 0-3 R²³, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R²³;-   R²³ is independently selected at each occurrence from the group: a    bond to the linking group, a bond to the targeting moiety, ═O, F,    Cl, Br, I, —CF₃, —CN, —CO₂R²⁴, —C(═O)R²⁴, —C(═O)N(R²⁴)₂, —CHO,    —CH₂OR²⁴, —OC(═O)R²⁴, —OC(═O)OR^(24a), —OR²⁴, —OC(═O)N(R²⁴)₂,    —NR²⁵C(═O)R²⁴, —NR²⁵C(═O)OR^(24a), —NR²⁵C(═O)N(R²⁴)₂,    —NR²⁵SO₂N(R²⁴)₂, —NR²⁵SO₂R^(24a), —SO₃H, —SO₂R^(24a), —SR²⁴,    —S(═O)R^(24a), —SO₂N(R²⁴)₂, —N(R²⁴)₂, —NHC(═S)NHR²⁴, ═NOR²⁴, NO₂,    —C(═O)NHOR²⁴, —C(═O)NHNR²⁴R^(24a), —OCH₂CO₂H, 2-(1-morpholino)    ethoxy, C₁-C₅ alkyl, C₂-C₄ alkenyl, C₃-C₆ cycloalkyl, C₃-C₆    cycloalkylmethyl, C₂-C₆ alkoxyalkyl, aryl substituted with 0-2 R²⁴,    and a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O; and-   wherein at least one of A¹, A², A³, A⁴, A⁵, A⁶, A⁷, A⁸ or R²³ is a    bond to the linking group or targeting moiety;-   R²⁴, R^(24a), and R²⁵ are independently selected at each occurrence    from the group: a bond to the linking group, a bond to the targeting    moiety, H, C₁-C₆ alkyl, phenyl, benzyl, C₁-C₆ alkoxy, halide, nitro,    cyano, and trifluoromethyl; and-   R²⁶ is a co-ordinate bond to a metal or a hydrazine protecting    group; or-   a pharmaceutically acceptable salt thereof.    (32) A diagnostic agent according to Embodiment 31, wherein:-   h′ is 1;-   W² is NH; and-   x′ is 1.    (33) A diagnostic agent according to any one of embodiments 1,    wherein:-   x is 0;-   Z is aryl substituted with 0-3 R¹⁶;-   k is 1;-   g′ is 1;-   R^(13a)R^(14a) are independently H;-   W² is NHC(═O) or —(OCH2CH2)₇₆₋₈₄-; and-   x′ is 1.    (34) A diagnostic agent according to any one of embodiments 31-33,    wherein:-   W¹ is C═O;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (35) A diagnostic agent according to any one of embodiment 31-34,    wherein:-   2-{[5-(3-{2-[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-acetylamino}-propylcarbamoyl)-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonic    acid;-   2-{[5-(4-{[(6-Hydroxycarbamoyl-7-isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-10-carbonyl)-amino]-methyl}-benzylcarbamoyl)-pyridin-2-yl]-hydrazonomethyl}-benzenesulfonic    acid;-   2-[7-({N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]carbamoyl}methyl)-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl]acetic    acid;-   2-{7-[(N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-carbonylamino}methyl)phenyl]methyl}carbamoyl)methyl]-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl}acetic    acid;-   2-(7-{[N-(1-(N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]carbamoyl}-2-sulfoethyl)carbamoyl]methyl}-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl)acetic    acid;-   2-(7({N-[1-(N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-carbonylamino}methyl)phenyl]methyl}carbamoyl)-2-sulfoethyl]carbamoyl}methyl)-1,4,7,10-tetraaza-4,10-bis(carboxymethyl)cyclododecyl)acetic    acid;-   2-({2-[({N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]carbamoyl}methyl)(carboxymethyl)amino}ethyl){2-[bis(carboxymethyl)amino]ethyl}amino]acetic    acid;-   2-[(2-{[N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-carbonylamino}methyl)phenyl]methyl}carbamoyl)methyl](carboxymethyl)amino}ethyl){2-[bis(carboxymethyl)amino]ethyl}amino]acetic    acid;-   N-[3-(2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}acetylamino)propyl]-4,5-bis[2-(ethoxyethylthio)acetylamino]pentanamide;-   N-{[4-({[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}methyl)-phenyl]methyl}-4,5-bis[2-(ethoxyethylthio)acetylamino]-pentanamide;-   1-(1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamino)-α,ω-dicarbonylPEG₃₄₀₀-2-{[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]carbonylamino}-N-(3-aminopropyl)acetamide;-   1-(1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamino)-α,ω-dicarbonylPEG₃₄₀₀-[7-(N-hydroxycarbamoyl)(3S,6R,7S)-4-aza-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-trien-3-yl]-N-{[4-(aminomethyl)phenyl]methyl}carboxamide    conjugate;-   2-[2-({5-[N-(5-(N-hydroxycarbamoyl)(5R)-5-{3-[4-(3,4-dimethoxyphenoxy)phenyl]-3-methyl-2-oxopyrrolidinyl}pentyl)carbamoyl](2-pyridyl)}amino)(1Z)-2-azavinyl]benzenesulfonic    acid;-   2-(2-{[5-(N-{3-[3-(N-hydroxycarbamoyl)(4S)-4-({4-[(4-methylphenyl)methoxy]piperidyl}carbonyl)piperidyl]-3-oxopropyl}carbamoyl)(2-pyridyl)]amino}(1Z)-2-azavinyl)benzenesulfonic    acid; and

(36) A diagnostic agent according to any one of embodiments 31-35wherein the diagnostic metal is selected from the group consisting of: aparamagnetic metal, a ferromagnetic metal, a gamma-emittingradioisotope, or an x-ray absorber.(37) A diagnostic agent according to any one of embodiments 31-36wherein the diagnostic metal is radioisotope selected from the groupconsisting of ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga.(38). A diagnostic agent according to any one of embodiments 31-37further comprising a first ancillary ligand and a second ancillaryligand capable of stabilizing the radioisotope.(39) A diagnostic agent according to Embodiment 37, wherein theradioisotope is ^(99m)Tc.(40) A diagnostic agent according to Embodiment 37, wherein theradioisotope is ¹¹¹In.(41) A diagnostic agent according to embodiment 36 wherein theparamagnetic metal ion is selected from the group consisting of Gd(III),Dy(III), Fe(III), and Mn(II).(42). A diagnostic agent according to embodiment 36 wherein the x-rayabsorber is a metal is selected from the group consisting of: Re, Sm,Ho, Lu, Pm, Y, Bi, Pd, Gd, La, Au, Au, Yb, Dy, Cu, Rh, Ag, and Ir.(43) A diagnostic composition comprising a compound according to any oneof embodiments 1-42 or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.(44) A kit comprising a compound of to any one of embodiments 1-42, or apharmaceutically acceptable salt form thereof and a pharmaceuticallyacceptable carrier.(45) A kit according to Embodiment 44, wherein the kit further comprisesone or more ancillary ligands and a reducing agent.(46) A kit according to Embodiment 45, wherein the ancillary ligands aretricine and TPPTS.(47) A kit according to Embodiment 45, wherein the reducing agent istin(II).(48) A diagnostic agent comprising an echogenic gas and a compound,wherein the compound comprises:

-   i) 1-10 targeting moieties;-   ii) a surfactant (Sf); and-   iii) 0-1 linking groups between the targeting moiety and surfactant;    wherein the targeting moiety is a matrix metalloproteinase    inhibitor; and-   wherein the surfactant is capable of forming an echogenic gas filled    lipid sphere or microbubble.    (49) A diagnostic agent according to embodiment 48, wherein the    targeting moiety is a matrix metalloproteinase inhibitor having an    inhibitory constant K_(i) of <1000 nM.    (50) A diagnostic agent according to any one of embodiments 48-49,    wherein the targeting moiety is a matrix metalloproteinase inhibitor    having an inhibitory constant K_(i) of <100 nM.    (51) A diagnostic agent according to embodiment 48, comprising 1-5    targeting moieties.    (52). A diagnostic agent according to embodiment 48, comprising one    targeting moiety.    (53) A diagnostic agent according to any one of embodiments 48-52,    wherein the targeting moiety is an inhibitor of one or more matrix    metalloproteinases selected from the group consisting of MMP-1,    MMP-2, MMP-3, MMP-9, and MMP-14.    (54) A diagnostic agent according to any one of embodiments 48-53,    wherein the targeting moiety is an inhibitor of one or more matrix    metalloproteinases selected from the group consisting of MMP-2,    MMP-9, and MMP-14.    (55) A diagnostic agent according to embodiment 48, wherein the    targeting moiety is of the formulae (Ia) or (Ib):

wherein,

-   R is independently OH or —CH₂SH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₂₀ alkyl;-   X is independently C═O or SO₂, provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶;

-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to the    linking group or a bond to the surfactant;-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with a bond to    the linking group or a bond to the surfactant;-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to the    linking group or a bond to the surfactant; or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Sf, and —C(═O)—NR²⁹R³⁰;-   R⁸ is independently at each occurrence OH or phenyl, optionally    substituted with a bond to the linking group or a bond to the    surfactant, provided that when R⁸ is phenyl, R¹⁰ is    —C(═O)—CR¹²—NH—CH(CH₃)—COOH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to the linking group or a bond to the surfactant, or are    taken together with the carbon atom to which R⁹ and R^(9′) are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system substituted with R⁶ and optionally    substituted with a bond to the linking group or a bond to the    surfactant;-   R¹⁰ and R¹¹ are independently N, or C₁₋₆ alkyl optionally    substituted with a bond to the linking group or a bond to the    surfactant, or are taken together with the nitrogen atom to which    they are attached to form a 5-7 atom saturated, partially    unsaturated or aromatic ring system containing 0-3 heteroatoms    selected from O, N, SO₂ and S, said ring system optionally    substituted with 0-3 R²⁷, a bond to the linking group or a bond to    the surfactant;-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₂ and S, said ring system optionally substituted with a bond to    the linking group or a bond to the surfactant; and-   R¹² is independently C₁₋₂₀ alkyl;-   R²⁷ is ═O, C₁₋₄ alkyl, or phenyl substituted with R²⁸;-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C₁₋₄ alkyl.    (56) A diagnostic agent according to embodiment 55 wherein wherein    the targeting moiety is a matrix metalloproteinase inhibitor of the    formulae (Ia) or (Ib):

wherein,

-   R is OH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₆ alkyl;-   X is C═O;-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to the    linking group or a bond to the surfactant;-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with a bond to    the linking group or a bond to the surfactant;-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to the    linking group or a bond to the surfactant; or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Sf, and —C(═O)—NR²⁹R³⁰;-   R⁸ is OH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to the linking group or a bond to the surfactant, or are    taken together with the carbon atom to which R⁹ and R^(9′) are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with a bond to the linking    group or a bond to the surfactant;-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to the linking group or a bond to the    surfactant, or are taken together with the nitrogen atom to which    they are attached to form a 5-7 atom saturated, partially    unsaturated or aromatic ring system containing 0-1 heteroatoms    selected from O, N, said ring system optionally substituted with 0-3    R²⁷, a bond to the linking group or a bond to the surfactant;-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-1 heteroatoms selected from O, N,    said ring system optionally substituted with a bond to the linking    group or a bond to the surfactant; and-   R¹² is independently C₁₋₆ alkyl;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸;-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C1-4 alkyl.    (57) A diagnostic agent according to any one of embodiments 55-57    wherein the targeting moiety is a matrix metalloproteinase inhibitor    of the formulae (Ia) or (Ib):    wherein:-   R is —OH;-   R² is C₁₋₆ alkyl;-   X is C═O;-   R³ is

-   R¹ and R⁴ are taken together to form a bridging group of formula    —(CH₂)₃—O-phenyl-CH₂—;-   R⁵ is NH(C1-6alkyl), substituted with a bond to the linking group or    a bond to the surfactant.    (58) A diagnostic agent according to any one of embodiments 55-57    wherein:-   R is —OH;-   R⁹ is C₁ alkyl substituted with a bond to Ln;-   R¹⁰ and R¹¹ taken together with the nitrogen atom to which they are    attached form a 5 atom saturated ring system, said right system is    substituted with 0-3 R²⁷;-   R²⁷ is ═O, C1-4 alkyl, or phenyl substituted with R²⁸; and-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups.    (59) A diagnostic agent according to any one of embodiments 55-58    wherein

R is —OH;

R¹ and R² taken together with the nitrogen and carbon atom through whichthey are attached form a C₅₋₇ atom saturated ring system substitutedwith one or more substituents selected from the group consisting of: abond to Ln, a bond to Sf, and —C(═O)—NR²⁹R³⁰;R²⁹ and R³⁰ taken together with the nitrogen atom through which they areattached form a C5-7 atom saturated ring system substituted with R³¹;andR³¹ is a benzyloxy group substituted with C1-4 alkyl.(60) A diagnostic agent according to any one of embodiments 48-59wherein the linking group is of the formula:

((W¹)_(h)-(CR¹³R¹⁴)_(g))_(x)—(Z)_(k)—((CR^(13a)R^(14a))_(g′)-(W²)_(h′))_(x′);

-   W¹ and W² are independently selected at each occurrence from the    group: O, S, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O),    C(═O)O, OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, SO₂NH, —(OCH₂CH₂)₇₆₋₈₄,    (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t),    and (aa)_(t′);-   as is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-3 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-3 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, PO₃H, C₁-C₅ alkyl    substituted with 0-3 R¹⁶, aryl substituted with 0-3 R¹⁶, benzyl    substituted with 0-3 R¹⁶, and C₁-C₅ alkoxy substituted with 0-3 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to the    surfactant;-   R¹⁶ is independently selected at each occurrence from the group: a    bond to the surfactant, COOR¹⁷, C(═O)NHR¹⁷, NHC(═O)R¹⁷, OH, NHR¹⁷,    SO₃H, PO₃H, —OPO₃H₂, —OSO₃H, aryl substituted with 0-3 R¹⁷, C₁₋₅    alkyl substituted with 0-1 R¹⁸, C₁₋₅ alkoxy substituted with 0-1    R¹⁸, and a 5-10 membered heterocyclic ring system containing 1-4    heteroatoms independently selected from N, S, and O and substituted    with 0-3 R¹⁷;-   R¹⁷ is independently selected at each occurrence from the group: H,    alkyl substituted with 0-1 R¹⁸, aryl substituted with 0-1 R¹⁸, a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-1    R¹⁸, C₃₋₁₀ cycloalkyl substituted with 0-1 R¹⁸, polyalkylene glycol    substituted with 0-1 R¹⁸, carbohydrate substituted with 0-1 R¹⁸,    cyclodextrin substituted with 0-1 R¹⁸, amino acid substituted with    0-1 R¹⁸, polycarboxyalkyl substituted with 0-1 R¹⁸, polyazaalkyl    substituted with 0-1 R¹⁸, peptide substituted with 0-1 R¹⁸, wherein    the peptide is comprised of 2-10 amino acids,    3,6-O-disulfo-B-D-galactopyranosyl, bis(phosphonomethyl)glycine, and    a bond to the surfactant;-   R¹⁸ is a bond to the surfactant;-   k is selected from 0, 1, and 2;-   h is selected from 0, 1, and 2;-   h′ is selected from 0, 1, and 2;-   g is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s″ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   x is selected from 0, 1, 2, 3, 4, and 5; and-   x′ is selected from 0, 1, 2, 3, 4, and 5.    (61) A diagnostic agent according to any one of embodiments 48-60    wherein-   W¹ and W² are independently selected at each occurrence from the    group: O, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O), C(═O)O,    OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, —(CH₂CH₂O)₇₆₋₈₄—, (OCH₂CH₂)_(s),    (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t), and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-1 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-1 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-1 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, C₁-C₅ alkyl    substituted with 0-1 R¹⁶, aryl substituted with 0-1 R¹⁶, benzyl    substituted with 0-1 R¹⁶, and C₁-C₅ alkoxy substituted with 0-1 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to the    surfactant;-   k is 0 or 1;-   s is selected from 0, 1, 2, 3, 4, and 5;-   s′ is selected from 0, 1, 2, 3, 4, and 5;-   s″ is selected from 0, 1, 2, 3, 4, and 5; and-   t is selected from 0, 1, 2, 3, 4, and 5.    (62) A diagnostic agent according to embodiment 60 wherein:-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (63) A diagnostic agent according to embodiment 60-   x is 0;-   k is 1;-   Z is aryl substituted with 0-3 R¹⁶;-   g′ is 1;-   W² is NH;-   R^(13a) and R^(14a) are independently H;-   h′ is 1; and-   x′ is 1.    (64) A diagnostic agent according to embodiment 60-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 1;-   R^(13a) and R^(14a) are independently H; or C1-5 alkyl substituted-   with 0-3 R¹⁶;-   R¹⁶ is SO₃H;-   W² is NHC(═O) or NH;-   h′ is 1; and-   x′ is 2.    (65) A diagnostic agent according to embodiment 60-   W¹ is C(═O)NH;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   x is 1,-   W² is —NH(C═O)— or —(OCH₂CH₂)₇₆₋₈₄—;-   h′ is 2; and-   x′ is 1.    (66) A diagnostic agent according to embodiment 60-   x is 0;-   k is 0;-   g′ is 3;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (67) A diagnostic agent according to embodiment 60-   x is 0;-   Z is aryl substituted with 0-3 R¹⁶,-   k is 1;-   g′ is 1;-   R^(13a)R^(14a) are independently H;-   W² is NHC(═O) or —(OCH2CH2)₇₆₋₈₄-; and-   x′ is 1.    (68) A diagnostic agent according to embodiment 60-   W¹ is C═O;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (69) A diagnostic agent according to embodiment 48 wherein the    linking group is present.    (70) A diagnostic agent according to any one of embodiments 48-69    wherein-   S_(f) is a surfactant which is a lipid or a compound of the formula:

-   A⁹ is selected from the group: OH and OR³²;-   A¹⁰ is OR³²;-   R³² is C(O)C₁₋₂₀ alkyl;-   E⁹ is C₁₋₁₀ alkylene substituted with 1-3 R³³;-   R³³ is independently selected at each occurrence from the group:-   R³⁵, —PO₃H—R³⁵, ═O, —CO₂R³⁴, —C(═O)R³⁴, —C(═O)N(R³⁴)₂, —CH₂OR³⁴,    —OR³⁴, —N(R³⁴)₂, C₁-C₅ alkyl, and C₂-C₄ alkenyl;-   R³⁴ is independently selected at each occurrence from the group:    R³⁵, H, C₁-C₆ alkyl, phenyl, benzyl, and trifluoromethyl;-   R³⁵ is a bond to L_(n);-   and a pharmaceutically acceptable salt thereof.    (71) A diagnostic agent according to any one of embodiments 48-70    wherein the surfactant is a lipid or a compound of the formula:

-   A⁹ is OR³²,-   A¹⁰ is OR³²;-   R³² is C(═O)C₁₋₁₅ alkyl,-   E⁹ is C₁₋₄ alkylene substituted with 1-3 R³³;-   R³³ is independently selected at each occurrence from the group:    R³⁵, —PO₃H—R³⁵, ═O, —CO₂R³⁴, —C(═O)R³⁴, —CH₂OR³⁴, —OR³⁴, and C₁-C₅    alkyl;-   R³⁴ is independently selected at each occurrence from the group:    R³⁵, H, C₁-C₆ alkyl, phenyl, and benzyl; and-   R³⁵ is a bond to L_(n).    (72) A diagnostic agent according to any one of embodiments 48-71,    wherein

wherein:

-   A¹ is a bond to Ln;-   E¹ is C₁ alkyl substituted by R²³;-   A² is NH;-   E² is C₂ alkyl substituted with 0-1R²³;-   A³ is —O—P(O) (R²¹)—O;-   E³ is C₁ alkyl;-   A⁴ and A⁵ are each —O—;-   E⁴ and E⁶ are each independently C₁₋₁₆ alkyl substituted with    0-1R²³;-   E⁵ is C₁ alkyl;-   A⁵ is —O—;-   R²¹ is —OH; and-   R²³ is ═O.    (73) A diagnostic agent according to embodiment 48 wherein the    compound is of the formula:

(Q)_(d)-L_(n)-S_(f)

wherein, Q is a compound of Formulae (Ia) or (Ib):

wherein,

-   R is independently OH or —CH₂SH;-   R¹ is independently selected at each occurrence from the group: H,    OH, C₁₋₃ alkyl, C₂₋₃ alkenyl, C₂₋₃ alkynyl, and heterocycle-S—CH₂—;-   R² is independently C₁₋₂₀ alkyl;-   X is independently C═O or SO₂, provided when X is C═O, R³ is

and when X is SO₂, R³ is independently selected from the group: arylsubstituted with 0-2 R⁶, and heterocycle substituted with 0-2 R⁶;

-   R⁴ is independently selected at each occurrence from the group: C₁₋₆    alkyl, phenyl, and benzyl;-   R⁵ is independently at each occurrence from the group: NH(C₁₋₆    alkyl), NH-phenyl, and NH-heterocycle; wherein said alkyl, phenyl    and heterocycle groups are optionally substituted with a bond to    L_(n);-   R⁶ is independently aryloxy substituted with 0-3 R⁷;-   R⁷ is independently halogen or methoxy;-   or alternatively,-   R¹ and R⁴ may be taken together to form a bridging group of the    formula —(CH₂)₃—O-phenyl-CH₂—, optionally substituted with a bond to    L_(n);-   or alternatively,-   R¹ and R² may be taken together to form a bridging group of the    formula —(CH₂)₃—NH—, optionally substituted with a bond to L_(n); or-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Sf, and —C(═O)—NR²⁹R³⁰;-   R⁸ is independently at each occurrence OH or phenyl, optionally    substituted with a bond to L_(n), provided that when R⁸ is phenyl,    R¹⁰ is —C(═O)—CR¹²—NH—CH(CH₃)—COOH;-   R⁹ and R^(9′) are independently H, C₁₋₆ alkyl optionally substituted    with a bond to L_(n), or are taken together with the carbon atom to    which they are attached to form a 5-7 atom saturated, partially    unsaturated or aromatic ring system containing 0-3 heteroatoms    selected from O, N, SO₂ and S, said ring system substituted with R⁶    and optionally substituted with a bond to L_(n);-   R¹⁰ and R¹¹ are independently H, or C₁₋₆ alkyl optionally    substituted with a bond to L_(n), or are taken together with the    nitrogen atom to which they are attached to form a 5-7 atom    saturated, partially unsaturated or aromatic ring system containing    0-3 heteroatoms selected from O, N, SO₂ and S, said ring system    optionally substituted with 0-3 R²⁷ or a bond to L_(n);-   or alternatively,-   R⁹ and R¹⁰ are taken together with the carbon atom to which they are    attached to form a 5-7 atom saturated, partially unsaturated or    aromatic ring system containing 0-3 heteroatoms selected from O, N,    SO₃ and S, said ring system optionally substituted with a bond to    L_(n);-   R¹² is independently C₁₋₂₀ alkyl;-   d is selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   L_(n) is a linking group having the formula:

((W¹)_(h)-(CR¹³R¹⁴)_(g))_(x)—(Z)_(k)—((CR^(13a)R^(14a))_(g′)-(W²)_(h′))_(x′);

-   W¹ and W² are independently selected at each occurrence from the    group: O, S, NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O),    C(═O)O, OC(═O), NHC(═S)NH, NHC(═O)NH, SO₂, SO₂NH, —(OCH₂CH₂)₇₆₋₈₄,    (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′), (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t),    and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-3 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-3 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-3 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, PO₃H, C₁-C₅ alkyl    substituted with 0-3 R¹⁶, aryl substituted with 0-3 R¹⁶, benzyl    substituted with 0-3 R¹⁶, and C₁-C₅ alkoxy substituted with 0-3 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, R¹⁷, and a bond to Sf;-   R¹⁶ is independently selected at each occurrence from the group: a    bond to Sf, COOR¹⁷, C(═O)NHR¹⁷, NHC(═O)R¹⁷, OH, NHR¹⁷, SO₃H, PO₃H,    —OPO₃H₂, —OSO₃H, aryl substituted with 0-3 R¹⁷, C₁₋₅ alkyl    substituted with 0-1 R¹⁸, C₁₋₅ alkoxy substituted with 0-1 R¹⁸, and    a 5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-3    R¹⁷;-   R¹⁷ is independently selected at each occurrence from the group: H,    alkyl substituted with 0-1 R¹⁸, aryl substituted with 0-1 R¹⁸, a    5-10 membered heterocyclic ring system containing 1-4 heteroatoms    independently selected from N, S, and O and substituted with 0-1    R¹⁸, C₃₋₁₀ cycloalkyl substituted with 0-1 R¹⁸, polyalkylene glycol    substituted with 0-1 R¹⁸, carbohydrate substituted with 0-1 R¹⁸,    cyclodextrin substituted with 0-1 R¹⁸, amino acid substituted with    0-1 R¹⁸, polycarboxyalkyl substituted with 0-1 R¹⁸, polyazaalkyl    substituted with 0-1 R¹⁸, peptide substituted with 0-1 R¹⁸, wherein    the peptide is comprised of 2-10 amino acids,    3,6-O-disulfo-B-D-galactopyranosyl, bis(phosphonomethyl)glycine, and    a bond to Sf;-   R¹⁸ is a bond to Sf;-   k is selected from 0, 1, and 2;-   h is selected from 0, 1, and 2;-   h′ is selected from 0, 1, and 2;-   g is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   g′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   s″ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   t′ is selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;-   x is selected from 0, 1, 2, 3, 4, and 5;-   x′ is selected from 0, 1, 2, 3, 4, and 5;-   S_(f) is a surfactant which is a lipid or a compound of the formula:

-   A⁹ is selected from the group: OH and OR³²;-   A¹⁰ is OR³²;-   R³² is C(═O)C₁₋₂₀ alkyl;-   E⁹ is C₁₋₁₀ alkylene substituted with 1-3 R³³:-   R³³ is independently selected at each occurrence from the group:    R³⁵, —PO₃H—R³⁵, ═O, —CO₂R³⁴, —C(═O)R³⁴, —C(═O)N(R³⁴)₂, —CH₂OR³⁴,    —OR³⁴, —N(R³⁴)₂, C₁-C₅ alkyl, and C₂-C₄ alkenyl;-   R³⁴ is independently selected at each occurrence from the group:    R³⁵, H, C₁-C₆ alkyl, phenyl, benzyl, and trifluoromethyl;-   R³⁵ is a bond to L_(n); or-   Sf is of the formula:

wherein:

-   A¹ is a bond to Ln;-   E¹ is C₁ alkyl substituted by R²³;-   A² is NH;-   E² is C₂ alkyl substituted with 0-1R²³;-   A³ is —O—P(O) (R²¹)—O;-   E³ is C₁ alkyl;-   A⁴ and A⁵ are each —O—;-   E⁴ and E⁶ are each independently C₁₋₁₆ alkyl substituted with 0-1R³;-   E⁵ is C₁ alkyl;-   A⁵ is —O—;-   R²¹ is —OH; and-   R²³ is ═O; or-   a pharmaceutically acceptable salt thereof.    (74) A diagnostic agent according to embodiment 73, wherein:-   R is —OH;-   R² is C1-6 alkyl;-   X is C═O;-   R³ is

-   R¹ and R⁴ are taken together to form a bridging group of formula    —(CH₂)₃—O-phenyl-CH₂—;-   R⁵ is NH(C1-6alkyl), substituted with a bond to the linking group or    a bond to the surfactant.    (75) A diagnostic agent according to any one of embodiments 73-74,    wherein:-   R is —OH;-   R⁹ is C₁ alkyl substituted with a bond to Ln;

R¹⁰ and R¹¹ taken together with the nitrogen atom to which they areattached form a 5 atom saturated ring system, said right system issubstituted with 0-3 R²⁷;

-   R²⁷ is ═O, C₁₋₄ alkyl, or phenyl substituted with R²⁸; and-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   S_(f) is a surfactant which is a lipid or a compound of the formula:

-   A⁹ is OR³²;-   A¹⁰ is OR³²;-   R³² is C(═O)C₁₋₁₅ alkyl;-   E⁹ is C₁₋₄ alkylene substituted with 1-3 R³³;-   R³³ is independently selected at each occurrence from the group:    R³⁵, —PO₃H—R³⁵, ═O, —CO₂R³⁴, —C(═O)R³⁴, —CH₂OR³⁴, —OR³⁴, and C₁-C₅    alkyl;-   R³⁴ is independently selected at each occurrence from the group:    R³⁵, H, C₁-C₆ alkyl, phenyl, and benzyl; and R³⁵ is a bond to L_(n).    (76) A diagnostic agent according to any one of embodiments 73-75,    wherein:-   R is —OH;-   R⁹ is C₁ alkyl substituted with a bond to Ln;-   R¹⁰ and R¹¹ taken together with the nitrogen atom to which they are    attached form a 5 atom saturated ring system, said right system is    substituted with 0-3 R²⁷;-   R²⁷ is ═O, C₁₋₄ alkyl, or phenyl substituted with R²⁸; and-   R²⁸ is a phenoxy group substituted with 0-2 OCH₃ groups;-   S_(f) is a surfactant which is a lipid or a compound of the of the    formula:

wherein:

-   A¹ is a bond to Ln;-   E¹ is C₁ alkyl substituted by R²³;-   A² is NH;-   E² is C₂ alkyl substituted with 0-1R²³;-   A³ is —O—P(O)(R²¹)—O;-   E³ is C₁ alkyl;-   A⁴ and A⁵ are each —O—;-   E⁴ and E⁶ are each independently C₁₋₁₆ alkyl substituted with    0-1R²³;-   E⁵ is C₁ alkyl;-   A⁵ is —O—;-   R²¹ is —OH; and-   R²³ is ═O.    (77) A diagnostic agent according to any one of embodiments 73-76,    wherein:    wherein-   R is —OH;-   R¹ and R² taken together with the nitrogen and carbon atom through    which they are attached form a C₅₋₇ atom saturated ring system    substituted with one or more substituents selected from the group    consisting of: a bond to Ln, a bond to Sf, and —C(═O)—NR²⁹R³⁰;-   R²⁹ and R³⁰ taken together with the nitrogen atom through which they    are attached form a C5-7 atom saturated ring system substituted with    R³¹; and-   R³¹ is a benzyloxy group substituted with C₁₋₄ alkyl.-   d is selected from 1, 2, 3, 4, and 5;-   W is independently selected at each occurrence from the group: O,    NH, NHC(═O), C(═O)NH, NR¹⁵C(═O), C(═O)NR¹⁵, C(═O), C(═O)O, OC(═O),    NHC(═S)NH, NHC(═O)NH, SO₂, (OCH₂CH₂)_(s), (CH₂CH₂O)_(s′),    (OCH₂CH₂CH₂)_(s″), (CH₂CH₂CH₂O)_(t), and (aa)_(t′);-   aa is independently at each occurrence an amino acid;-   Z is selected from the group: aryl substituted with 0-1 R¹⁶, C₃₋₁₀    cycloalkyl substituted with 0-1 R¹⁶, and a 5-10 membered    heterocyclic ring system containing 1-4 heteroatoms independently    selected from N, S, and O and substituted with 0-1 R¹⁶;-   R¹³, R^(13a), R¹⁴, R^(14a), and R¹⁵ are independently selected at    each occurrence from the group: H, ═O, COOH, SO₃H, C₁-C₅ alkyl    substituted with 0-1 R¹⁶, aryl substituted with 0-1 R¹⁶, benzyl    substituted with 0-1 R¹⁶, and C₁-C₅ alkoxy substituted with 0-1 R¹⁶,    NHC(═O)R¹⁷, C(═O)NHR¹⁷, NHC(═O)NHR¹⁷, NHR¹⁷, NHR¹⁷, R¹⁷, and a bond    to Sf;-   k is 0 or 1;-   s is selected from 0, 1, 2, 3, 4, and 5;-   s′ is selected from 0, 1, 2, 3, 4, and 5;-   s″ is selected from 0, 1, 2, 3, 4, and 5; and-   t is selected from 0, 1, 2, 3, 4, and 5.    (78) A diagnostic agent according to according to any one of    embodiments 73-77, wherein:-   W¹ is C(═O)NR¹⁵;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (79) A diagnostic agent according to embodiment 73, wherein:-   x is 0;-   k is 1;-   Z is aryl substituted with 0-3 R¹⁶;-   g′ is 1;-   W² is NH;-   R^(13a) and R^(14a) are independently H;-   h′ is 1; and-   x′ is 1.    (80) A diagnostic agent according to Embodiment 73, wherein:-   W¹ is C(═O)NR¹⁵,-   h is 1;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   x is 1;-   k is 0;-   g′ is 1;-   R^(13a) and R^(14a) are independently H; or C₁₋₅ alkyl substituted-   with 0-3 R¹⁶;-   R¹⁶ is SO₃H;-   W² is NHC(═O) or NH;-   h′ is 1; and-   x′ is 2.    (81) A diagnostic agent according to Embodiment 73, wherein:-   W¹ is C(═O)NH;-   h is 1;-   g is 3;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   x is 1;-   W² is —NH(C═O)— or —(OCH₂CH₂)₇₆₋₈₄—;-   h′ is 2; and-   x′ is 1.    (82) A diagnostic agent according to Embodiment 73, wherein:-   x is 0;-   k is 0;-   g′ is 3;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (83) A diagnostic agent according to Embodiment 73, wherein:-   x is 0;-   Z is aryl substituted with 0-3 R¹⁶;-   k is 1;-   g′ is 1;-   R^(13a)R^(14a) are independently H;-   W² is NHC(═O) or —(OCH2CH2)₇₆₋₈₄-; and-   x′ is 1.    (84) A diagnostic agent according to Embodiment 73, wherein:-   W¹ is C═O;-   g is 2;-   R¹³ and R¹⁴ are independently H;-   k is 0;-   g′ is 0;-   h′ is 1;-   W² is NH; and-   x′ is 1.    (85) A diagnostic agent according to Embodiment 1, wherein the    compound is selected from the group consisting of:

(86) A diagnostic agent according to embodiment 48, wherein: wherein theechogenic gas is a perfluorocarbon gas or sulfur hexafluoride.(87) A diagnostic agent according to embodiment 86 wherein saidperfluorocarbon is selected from the group consisting ofperfluoromethane, perfluoroethane, perfluoropropane, perfluorobutane,perfluorocyclobutane, perfluoropentane, and perfluorohexane.(88) A diagnostic composition comprising a compound according toembodiment 48 or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.(89) A diagnostic composition comprising a compound according toembodiment 48 or a pharmaceutically acceptable salt form thereof, anechogenic gas and a pharmaceutically acceptable carrier.(90) A diagnostic composition comprising a compound according toembodiment 48 further comprising:1,2-dipalmitoyl-an-glycero-3-phosphotidic acid,1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine, andN-(methoxypolyethylene glycol 5000carbamoyl)-1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine.

c. Third Non-Limiting Set of Embodiments of Imaging Agents or PrecursorsThereof

Matrix metalloproteinase (MMP) activity and extracellular matrixdegradation is dependent on the comparative balance between MMPs andTIMPs. Elevated TIMP activity suppresses angiogenesis via inhibition ofendothelial cell migration. TIMPs and synthetic small molecules ormatrix metalloproteinase inhibitors have therapeutic potential fordiseases involving elevated levels of MMP activity (Whittaker, M. et al,Chem. Rev., 1999, 99, 2735-2776; Babine, R. E. et al, Chem. Rev., 1997,97, 1359; De, B. et al, Ann. N.Y. Acad. Sci., 1999, 878, 40-60; Summers,J. B. et al, Annual Reports in Med. Chem., 1998, 33, 131).

A functional group, such as —CONH—OH, —COOH, or —SH, is necessary for amolecule to be an effective inhibitor of MMPs. This functional group isinvolved in the chelation of the active site zinc ion, and is commonlyreferred to as the zinc binding group or ZBG. The hydroxamate, forexample, is a bidentate ligand for zinc.

In some embodiments, a compound comprises the formula,(Q)_(d)-L_(n)-(C_(h)—X), (Q)_(d)-L_(n)-(C_(n)—X¹)_(d′),(Q)_(d)-L_(n)-(C_(h)—X²)_(d″), or (Q)_(d)-L_(n)-(C_(h)—X³), wherein Qrepresents a compound that inhibits a matrix metalloproteinase, d is1-10, d′=1-100, d″ is 1-100, Ln represents an optional linking group,C.sub.h represents a metal chelator or bonding moiety, X represents aradioisotope, X¹ represents paramagnetic metal ion, X² represents aparamagnetic metal ion or heavy atom containing insoluble solidparticle, and X³ represents a surfactant microsphere of an echogenicgas.

One class of compounds that that inhibits a matrix metalloproteinase(e.g., Q) are succinyl hydroxamates. A generic structure of succinylhydroxamate is shown below (1-1).

The ethylene spacer between the ZBG (—CONH—OH) and the succinyl amide isessential for potent activity. Substitution at P₁ tends to conferbroad-spectrum activity on the MMPIs. Substituents at this position, ingeneral, tend to point away from the enzyme. Moieties capable ofhydrogen bonding and lipophilic substituents at the P₁ position α to thehydroxamate (Johnson, W. H. et al, J. Enz. Inhib., 1987, 2, 1) tend toenhance activity (1-2). Incorporation of a hydroxyl group (Beckett, P.R., et al, Drug Discovery Today, 1996, 1, 16) at that position improvesoral activity in some case (1-3).

Substituents at the P₁′ position on the succinyl hydroxamates tend toimpart selectivity to the MMPIs. The S₁′ pocket is deep for MMP-2,MMP-3, MMP-8 and MMP-9 and occluded (short) for MMP-1 and MMP-7. A longalkyl substituent at the P₁′ position, for example, imparts selectivity(Miller, A. et al, Bioorg. Med. Chem. Lett., 1997, 7, 193) for MMP-2over MMP-1 and MMP-3 (1-4 and 1-5).

Substituents at the P₂′ position also point away from the enzyme. The P₁and the P₂′ positions can be linked (Xue, C-B. et al, J. Med. Chem.,1998, 41, 1745; Steinman, D. H. et al, Bioorg. Med. Chem. Lett., 1998,8, 2087) to form a macrocycle (1-6). Compounds such as (1-6) alsoexhibit nanomolar activity.

The nature of the macrocycle also imparts some selective inhibitionamong the MMPs. The P₂′ and the P₃′ positions may be cyclized to formlactams. The size of the lactam governs the selectivity.

The P₃′ position is a relatively open area in the succinyl hydroxamates,and a wide range of substitutents (for example (1-7)) may be introduced(Sheppard, G. S. et al, Bioorg. Med. Chem. Lett., 1998, 8, 3251) at thisposition. This position also offers the flexibility of attaching theoptional linker, L_(n), the chelator(s0, C_(h), for the imageablemoieties X and X¹, and the imageable moieties, X² and X³.

Other succinyl hydroxamates with modified P₂′ and P₃′ positions, such as(1-8) also have shown potent inhibition of MMPs. Those compounds andsyntheses of them are further described in the following patentapplications which are hereby incorporated by reference into this patentapplication: U.S. patent application Ser. No. 08/743,439, 60/127,594,and 60/127,635 and U.S. Pat. Nos. 6,057,336, 6,576,664, 6,455,522,6,429,213, 6,365,587, 6,268,379, 6,495,548, 6,689,771, and 6,376,665

Another class of compounds of that inhibits a matrix metalloproteinase(e.g., Q) are sulfonamide hydroxamates, such as (1-9) and (1-10).Modification of the isopropyl substituent in (1-10) results in deeppocket MMP selectivity, for example MMP-2 vs MMP-1 (Santos, O. et al.,J. Clin. Exp. Metastasis, 1997, 15, 499; MacPherson, L. J. et al, J.Med. Chem., 1997, 40, 2525).

Additional examples of inhibitors, Q, include the derivatized alaninehydroxamates, such as compounds (1-11) and (1-12), which showselectivity for MMP-2 and MMP-9 over the other MMPs. The P₁ position isavailable for limited modification as described in the patents andapplications incorporated by reference above. Those compounds andsyntheses of them are further described in the following patentapplications which are hereby incorporated by reference into this patentapplication: U.S. patent application Ser. No. 08/743,439, 60/127,594,and 60/127,635 and U.S. Pat. Nos. 6,057,336, 6,576,664, 6,455,522,6,429,213, 6,365,587, 6,268,379, 6,495,548, 6,689,771, and 6,376,665

Other compounds with selectivity for MMP-2 and MMP-9 over MMP-1 include(1-13). In this example the alpha position has a quaternary carbon andthe molecule does not contain any stereo centers (Lovejoy, B. et al.,Nature Struct. Biol., 1999, 6, 217).

In the non-hydroxamate series, a number of compounds have been reportedwith a variety of structures. Use of carboxylic acid as the ZBG has alsoreceived attention. In the case of compound (1-14), significantselectivity for MMP-2 (vs MMP-1) was observed when X=butyl vs X=H(Sahoo, S. P. et al, Bioorg. Med. Chem. Lett., 1995, 5, 2441).

Although thiols are monodentate ZBGs, some succinyl thiols such as(1-15) have exhibited good activity (Levin, J. I. et al, Bioorg. Med.Chem. Lett., 1998, 8, 1163). The P₃′ position may be utilized toconjugate a variety of linkers and chelators (as described above) forthe preparation of diagnostic agents. For example, the P₃′ position maybe utilized to attach the optional linker, L_(n), the chelator(s),C_(h), for the imageable moieties X and X¹, and the imageable moieties,X² and X³

In some embodiments, the pharmaceuticals are comprised of inhibitors, Q,which exhibit selectivity for MMP-1, MMP-2, MMP-3, MMP-9, or MMP-14alone or in combination over the other MMPs. Examples of moieties, Q,include compounds 1-4, 1-5, 1-6, 1-8, 1-9, 1-10, 1-11, 1-12, and 1-13.

In some embodiments, the inhibitors, Q, is selected to exhibitselectivity for MMP-2, MMP-9, or MMP-14 alone or in combination over theother MMPs. Examples of the such moieties, Q, include compounds 1-6,1-8, 1-11, and 1-12.

Such pharmaceuticals can be synthesized by several approaches. Oneapproach involves the synthesis of the targeting MMP inhibiting moiety,Q, and direct attachment of one or more moieties, Q, to one or moremetal chelators or bonding moieties, C_(h), or to a paramagnetic metalion or heavy atom containing solid particle, or to an echogenic gasmicrobubble. Another approach involves the attachment of one or moremoieties, Q, to the linking group, L_(n), which is then attached to oneor more metal chelators or bonding moieties, C_(h), or to a paramagneticmetal ion or heavy atom containing solid particle, or to an echogenicgas microbubble. Another approach, useful in the synthesis ofpharmaceuticals wherein d is 1, involves the synthesis of the moiety,Q-L_(n), together, by incorporating residue bearing L_(n) into thesynthesis of the MMP inhibitor, Q. The resulting moiety, Q-L_(n), isthen attached to one or more metal chelators or bonding moieties, C_(h),or to a paramagnetic metal ion or heavy atom containing solid particle,or to an echogenic gas microbubble. Another approach involves thesynthesis of an inhibitor, Q, bearing a fragment of the linking group,L_(n), one or more of which are then attached to the remainder of thelinking group and then to one or more metal chelators or bondingmoieties, C_(h), or to a paramagnetic metal ion or heavy atom containingsolid particle, or to an echogenic gas microbubble.

The MMP inhibiting moieties, Q, optionally bearing a linking group,L_(n), or a fragment of the linking group, can be synthesized usingstandard synthetic methods known to those skilled in the art. Methodsinclude but are not limited to those methods described below.

Generally, peptides, polypeptides and peptidomimetics are elongated bydeprotecting the alpha-amine of the C-terminal residue and coupling thenext suitably protected amino acid through a peptide linkage using themethods described. This deprotection and coupling procedure is repeateduntil the desired sequence is obtained. This coupling can be performedwith the constituent amino acids in a stepwise fashion, or condensationof fragments (two to several amino acids), or combination of bothprocesses, or by solid phase peptide synthesis according to the methodoriginally described by Merrifield, J. Am. Chem. Soc., 85, 2149-2154(1963), the disclosure of which is hereby incorporated by reference.

d. Fourth Non-Limiting Set of Embodiments of Imaging Agents orPrecursors Thereof

In some embodiments, an imaging agent or imaging agent precursor isselected from the group consisting of:

Subjects

As used herein, “subject” includes, but is not limited to, vertebrates,more specifically a mammal (e.g., a human, horse, pig, rabbit, dog,sheep, goat, non-human primate, cow, cat, guinea pig or rodent), a fish,a bird or a reptile or an amphibian. In some embodiments, the subject isa human subject. As used herein, “patient” refers to a subject afflictedwith a disease or disorder. The term “patient” includes human andveterinary subjects.

In some instances, the subject is one that has not experienced acardiovascular insult such as a myocardial infarction.

In some instances, the subject is one that has experienced a myocardialinfarction. In some cases, the imaging methods may be performed withinhours, days, weeks, or months after the myocardial infarction. In someinstances, the imaging methods are performed repeatedly after amyocardial infarction including for example weekly, monthly, biannually,annually, etc. The imaging methods may be performed at differentfrequencies after a myocardial infarction. As an example, immediatelyafter a myocardial infarction, the methods may be performed on a weeklyor monthly basis for a period of time (e.g., 6 months or a year), andthereafter may be performed at a less regular interval (e.g., every 6months, or every year) for a period of time or indefinitely.

In some instances, the subject is one having atherosclerosis (e.g.,having symptoms of atherosclerosis). In some instances, the subject isone that does not have atherosclerosis (e.g., does not have symptoms ofatherosclerosis).

Increased Risk Vs. Normal Population

The invention contemplates, in part, detecting presence and in someinstances amount of an administered imaging agent (i.e., an MMPinhibitor linked to an imaging moiety) and comparing this to a controlin order to determine an increased risk of developing AF or otherindication (e.g., CAVD). The invention intends to determine an“above-normal” or “above-average” or “increased” risk of developing AFor other indication. An above-normal or above-average risk or increasedrisk is a risk that is greater than the risk of a normal subject or apopulation of normal subjects or a randomly selected population fordeveloping AF or other indication. In some instances, an above-normal orabove-average risk or increased risk is indicated by any level of MMPthat is greater than the MMP level of a control. In some instances, theincreased risk is further quantified by measuring the MMP level, whereinlower MMP levels indicate a lower “increased” risk and higher MMP levelsindicate a higher “increased” risk, provided that even the lower MMPlevels are still above normal or control levels.

The control level may be an MMP level determined using the same imagingagent in a normal subject (i.e., a subject that is known not to haveAF), or it may be the average MMP level in a population of normalsubjects, or it may be the average MMP level in a random sampling of thepopulation at large. The control level may be one that is determinedprior to the analysis of the subject rather than one that is determinedin real time. The control level may therefore be a level that isobtained and established on a periodic basis (e.g., every 6 months,every year, etc.).

It will be understood that all subjects may have some risk of developingAF or other indication (e.g., CAVD). This risk may be referred to hereinas the “normal risk.” The normal risk may be established on anindividual subject basis or on a population basis. For example, it maybe determined as the risk of a “normal” subject developing AF (i.e., asubject that is not known to have AF), or the average risk in a normalpopulation of developing AF, or the average risk in a randomly selectedsubpopulation from the population at large.

In still other embodiments, the invention further contemplatesdetermining an increased risk of developing AF based on clinical trialresults. As an example, a clinical trial may be performed that assessesMMP profile in a number of subjects and then follows those subjects overtime in order to determine the nature of the profile that correlateswith increased risk of AF. Those trials may be performed on subjectsthat previously had AF and that may have been treated with an AF therapy(such as but not limited to cardioversion), with an outcome ofdetermining a profile that correlates with subjects that do not have arecurrence of AF after the trial and/or determining a profile thatcorrelates with subjects that do have a recurrence of AF after thetrial. Such trials may then be used to set the threshold (or cut pointor control) to which future subjects are compared against.

Regardless of the control used, increased risk of developing AF (as aprimary event or as a recurrent event) and/or likelihood of respondingto a particular AF therapy (such as but not limited to cardioversion,ablation, pharmacological rate or rhythm control therapy, or implantablepacer) may be indicated by any MMP level that is above a control level,or it may be indicated by an MMP level that is at least 5%, 10%, 15%,20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%,90%, 95%, 100%, 200%, 300%, 400%, or 500%, or 10-fold, 20-fold, 50-fold,100-fold, 200-fold, 300-fold, 400-fold, or 500-fold more than thecontrol level.

Imaging

The invention contemplates administering, to a subject, an imaging agentof the invention and then acquiring one or more images of the subject.The images will typically comprise images of the subject's heart, inwhole or in part. Such images are therefore referred to herein as heartor cardiac images. Such images may comprise more than heart tissueand/or they may not comprise the entire heart tissue. In some instances,such images will comprise atrial myocardium, including left atrialmyocardium.

The imaging modality will be dictated by the imaging moiety linked tothe MMP inhibitor (and vice versa) as will be understood. In someembodiments, the imaging modality is single-photon emission computedtomography (referred to as SPECT or SPET), SPECT/CT, PET, ultrasound,MRI, and the like.

Myocardial (or Cardiac) Perfusion

In some instances, the invention further contemplates determiningmyocardial perfusion (i.e., blood flow through the heart) usingmyocardial perfusion imaging agents. In some instances, a measure ofmyocardial perfusion is used together with a measure of MMP levels.Myocardial perfusion imaging agents include but are not limited toflurpiridaz F18, Thallium-201, and Tc-Sestamibi.

In some cases, methods of the invention may include determining aparameter of, or the presence or absence of, myocardial ischemia, rest(R) and/or stress (S) myocardial blood flows (MBFs), coronary flowreserve (CFR), coronary artery disease (CAD), left ventricular ejectionfraction (LVEF), end-systolic volume (ESV), end-diastolic volume (EDV),and the like.

Atrial Fibrillation (AF)

AF is an abnormal heart rhythm (cardiac arrhythmia) which involves thetwo small, upper heart chambers (i.e., the atria). Heart beats in anormal heart begin after electricity generated in the atria by thesinoatrial node spreads through the heart and causes contraction of theheart muscle and pumping of blood. In AF, the regular electricalimpulses of the sinoatrial node are replaced by disorganized, rapidelectrical impulses which result in irregular heartbeats.

AF is the most common cardiac arrhythmia. An individual mayspontaneously alternate between AF and a normal rhythm (paroxysmal AF)or may continue with AF as the dominant cardiac rhythm without reversionto the normal rhythm (chronic AF).

AF is often asymptomatic, but may result in symptoms of palpitations,fainting, chest pain, or even heart failure. These symptoms areespecially common when AF results in a heart rate which is either toofast or too slow. In addition, the erratic motion of the atria leads toblood stagnation (stasis) which increases the risk of blood clots thatmay travel from the heart to the brain and other areas. Thus, AF is animportant risk factor for stroke, the most feared complication of AF.

The symptoms of AF may be treated with pharmacological agents which slowthe heart rate. Several such pharmacological agents as well aselectrical cardioversion may be used to convert AF to a normal heartrhythm. Surgical and catheter-based therapies may also be used toprevent AF in certain individuals. People with AF are often given bloodthinners such as warfarin to protect them from strokes.

The American Heart Association, American College of Cardiology, and theEuropean Society of Cardiology have proposed the followingclassification system based on simplicity and clinical relevance. “FirstDetected” refers to any patient newly diagnosed with AF, as the exactonset and chronicity of the disease is often uncertain. A patient with 2or more identified episodes of AF is said to have “recurrent” AF. Thisis further classified into “paroxysmal” and “persistent” based on whenthe episode terminates without therapy. AF is said to be “paroxysmal”when it terminates spontaneously within 7 days, most commonly within 24hours. “Persistent” or “chronic” AF is AF established for more thanseven days. Differentiation of paroxysmal from chronic or established AFis based on the history of recurrent episodes and the duration of thecurrent episode of AF. “Lone atrial fibrillation” (LAF) is defined as AFin the absence of clinical or echo cardiographic findings ofcardiopulmonary disease. Patients with LAF who are under 65 have thebest prognosis.

AF is usually accompanied by symptoms related to either rapid heart rateor embolization. Rapid and irregular heart rates may be perceived aspalpitations, exercise intolerance, and occasionally produce angina andcongestive symptoms of shortness of breath or edema. Sometimes thearrhythmia will be identified with the onset of a stroke or a transientischemic attack (TIA). It is not uncommon to identify AF on a routinephysical examination or electrocardiogram (ECG/EKG), as it may beasymptomatic in some cases. Paroxysmal AF is the episodic occurrence ofthe arrhythmia and may be difficult to diagnose. Episodes may occur withsleep or with exercise, and their episodic nature may require prolongedECG monitoring (e.g. a Holter monitor) for diagnosis.

AF is diagnosed on an electrocardiogram, an investigation performedroutinely whenever irregular heart beat is suspected. Characteristicfindings include absence of P waves, unorganized electrical activity intheir place, and irregularity of R-R interval due to irregularconduction of impulses to the ventricles. If paroxysmal AF is suspected,episodes may be documented with the use of Holter monitoring (continuousECG recording for 24 hours or longer).

Diagnosis of AF sometimes involves analysis of renal function andelectrolytes, as well as thyroid-stimulating hormone (commonlysuppressed in hyperthyroidism and of relevance if amiodarone isadministered for treatment) and a blood count. A chest X-ray isgenerally performed. In acute-onset AF associated with chest pain,cardiac troponins or other markers of damage to the heart muscle may beordered. Coagulation studies (INR/aPTT) are usually performed, asanticoagulant medication may be commenced. A transesophagealechocardiogram may be indicated to identify any intracardiac thrombus.

AF is linked to several cardiac causes, but may occur in otherwisenormal hearts. Known associations include carbon monoxide poisoning,high blood pressure, mitral stenosis (e.g. due to rheumatic heartdisease or mitral valve prolapse), mitral regurgitation, heart surgery,coronary artery disease, hypertrophic cardiomyopathy, excessive alcoholconsumption (“binge drinking” or “holiday heart syndrome”),hyperthyroidism, hyperstimulation of the vagus nerve, usually by havinglarge meals (“binge eating”), lung pathology (such as pneumonia, lungcancer, pulmonary embolism, sarcoidosis), pericarditis, intenseemotional turmoil, and congenital heart disease.

The main goals of treatment of AF are to prevent temporary circulatoryinstability and stroke. Rate control and rhythm control are principallyused to achieve the former, while anticoagulation may be required todecrease the risk of the latter. AF can cause disabling and annoyingsymptoms. Palpitations, angina, lassitude (weariness), and decreasedexercise tolerance are related to rapid heart rate and inefficientcardiac output caused by AF. Rate control treatments seek to reduce theheart rate to normal, usually 60 to 100 beats per minute. Rhythm controlseeks to restore the normal heart rhythm, called normal sinus rhythm.Studies suggest that rhythm control is mainly a concern in newlydiagnosed AF, while rate control is more important in the chronic phase.

AF with a persistent rapid rate can cause a form of heart failure calledtachycardia induced cardiomyopathy. This can significantly increasemortality and morbidity. The early treatment of AF through eitherrate-control or rhythm control can prevent this condition and therebyimprove mortality and morbidity.

Rate control methods include beta blockers (e.g. metoprolol), cardiacglycosides (e.g. digoxin), and calcium channel blockers (e.g.verapamil). These medications work by slowing the generation of impulsesfrom the atria and the conduction of those impulses from the atria tothe ventricles.

In refractory cases where none of the above drugs are sufficient, avariety of other antiarrhythmic drugs, most commonly includingquinidine, flecamide, propafenone, disopyramide, sotalol, or amiodaronemay be used. Of these, only propafenone, sotalol, and amiodarone (whichpossess some beta blocking activity) control the ventricular rate; theothers may maintain sinus rhythm, but may actually increase theventricular rate. Many of these drugs are less frequently used todaythan in the past. All (with the possible exception of amiodarone)increase the risk of ventricular tachycardia, which can be fatal. Insymptomatic patients with normal heart function, however, the smallincrease in risk is usually felt to be acceptable. In the presence ofheart failure, the only anti-arrhythmic drugs thought to be safe areamiodarone and dofetilide.

In patients with AF where rate control drugs are ineffective and it isnot possible to restore sinus rhythm using cardioversion,non-pharmacological alternatives are available. For example, to controlrate it is possible to destroy the bundle of cells connecting the upperand lower chambers of the heart—the atrioventricular node—whichregulates heart rate, and to implant a pacemaker instead.

A more complex technique involves ablating groups of cells near thepulmonary veins where AF is thought to originate, or creating moreextensive lesions in an attempt to prevent AF from establishing itself.

Rhythm control methods include electrical and chemical cardioversion.Electrical cardioversion involves the restoration of normal heart rhythmthrough the application of a DC (direct current) electrical shock.Chemical cardioversion is performed with drugs, such as amiodarone,propafenone or flecamide. Implantable pacing devices can also be usedfor rate management of AF patients and can be indicated versustraditional cardioversion.

The anti-arrhythmic medications often used in either pharmacologicalcardioversion or in the prevention of relapse to AF alter the flux ofions in heart tissue, making them less excitable, setting the stage forspontaneous and durable cardioversion. These medications are often usedin concert with electrical cardioversion.

Whichever method of cardioversion is used, approximately 50% of patientsrelapse within one year, although the continued daily use of oralantiarrhythmic drugs may extend this period. The key risk factor forrelapse is duration of AF, although other risk factors that have beenidentified include the presence of structural heart disease, andincreasing age.

Radiofrequency ablation (RFA) uses radiofrequency energy to destroyabnormal electrical pathways in heart tissue. It is used in recurrentAF. The energy emitting probe (electrode) is placed into the heartthrough a catheter. The practitioner first “maps” an area of the heartto locate the abnormal electrical activity before the responsible tissueis eliminated. Ablation is a newer technique and has shown some promisefor cases unresponsive to conventional treatments. New techniquesinclude the use of cryoablation (tissue freezing using a coolant whichflows through the catheter), and microwave ablation, where tissue isablated by the microwave energy “cooking” the adjacent tissue. Theabnormal electrophysiology can also be modified in a similar waysurgically, and this procedure referred to as the Cox maze procedure, iscommonly performed concomitantly with cardiac surgery. More recently,minimally invasive surgical variations on the Cox Maze procedure(“minimaze” procedures) have also been developed.

The Cox maze procedure is an open-heart surgical procedure intended toeliminate AF. “Maze” refers to the series of incisions made in the atria(upper chambers of the heart), which are arranged in a maze-likepattern. The intention was to eliminate AF by using incisional scars toblock abnormal electrical circuits (atrial macrorentry) that AFrequires. This procedure required an extensive series of endocardial(from the inside of the heart) incisions through both atria, a mediansternotomy (vertical incision through the breastbone) andcardiopulmonary bypass (heart-lung machine). A series of improvementswere made, culminating in 1992 in the Cox maze III procedure, which isnow considered to be the “gold standard” for effective surgical cure ofAF. The Cox maze III is sometimes referred to as the “traditional maze”,the “cut and sew maze”, or simply the “maze”.

Minimaze surgery is minimally invasive cardiac surgery intended to cureAF. Minimaze refers to “mini” versions of the original maze procedure.These procedures are less invasive than the Cox maze procedure and donot require a median sternotomy (vertical incision in the breastbone) orcardiopulmonary bypass (heart-lung machine). These procedures usemicrowave, radiofrequency, or acoustic energy to ablate atrial tissuenear the pulmonary veins.

In confirmed AF, anticoagulant treatment is a crucial way to preventstroke. Treatment of AF patients over age 60, who also have one or moreof: previous strokes (or warning strokes), hypertension (high bloodpressure), diabetes, or congestive heart failure, with warfarin (alsoknown as Coumadin® or Marevan®) results in a 60 to 70 percent reductionin the subsequent risk of stroke. Patients under age 65 who have anystructural heart disease (i.e. valvular heart disease, ejection fraction<=35%, history of heart attack) may also benefit from warfarin.

The use of warfarin is associated with a delayed clinical effect. Ittypically takes three to five days to achieve a demonstrableanticoagulant effect. Hence, if an immediate anticoagulant effect isrequired, physicians could use heparin or other heparinoids such asenoxaparin to provide early anticoagulation. In practice, urgentanticoagulation is seldom indicated. Even in the setting of strokecomplicating AF, clinical trial results do not support the routine useof immediate anticoagulation.

Patients under age 65 who do not have structural heart disease (i.e.with LAF) do not require warfarin, and can be treated with aspirin orclopidogrel. There is evidence that aspirin and clopidogrel areeffective when used together. The new anticoagulant ximelagatran hasbeen shown to prevent stroke with equal efficacy as warfarin.

Determining who should and should not receive anti-coagulation withanti-coagulant drugs (e.g., warfarin, ximegalatran, heparin or otherheparinoids) is not easy. The CHADS2 score is the best validated methodof determining risk of stroke (and therefore who should beanticoagulated). The UK NICE guidelines have instead opted for analgorithm approach. The underlying problem is that if a patient has ayearly risk of stroke that is less than 2%, then the risks associatedwith taking warfarin outweigh the risk of getting a stroke.

MMPs

Key contributors to ECM synthesis/degradation are the matrixmetalloproteinases (MMPs) and the endogenous tissue inhibitors of themetalloproteinases (TIMPs) (Visse R, et al. 2003; Matrisian L M, et al.1990).

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases;other family members are adamalysins, serralysins, and astacins. TheMMPs belong to a larger family of proteases known as the metzincinsuperfamily.

The MMPs share a common domain structure. The three common domains arethe pro-peptide, the catalytic domain and the haemopexin-like C-terminaldomain which is linked to the catalytic domain by a flexible hingeregion.

The MMPs are initially synthesized as inactive zymogens with apro-peptide domain that must be removed before the enzyme is active. Thepro-peptide domain is part of a “cysteine switch” that contains aconserved cysteine residue which interacts with the zinc in the activesite and prevents binding and cleavage of the substrate keeping theenzyme in an inactive form. In the majority of the MMPs, the cysteineresidue is in the conserved sequence PRCGxPD. Some MMPs have aprohormone convertase cleavage site (Furin-like) as part of this domainwhich when cleaved activates the enzyme. MMP-23A and MMP-23B include atransmembrane segment in this domain (PMID 10945999).

The MMPs can be subdivided in different ways. Use of bioinformaticmethods to compare the primary sequences of the MMPs suggests thefollowing evolutionary groupings of the MMPs: MMP-19; MMPs 11, 14, 15,16 and 17; MMP-2 and MMP-9; all the other MMPs.

Analysis of the catalytic domains in isolation suggests that thecatalytic domains evolved further once the major groups haddifferentiated, as is also indicated by the substrate specificities ofthe enzymes. The most commonly used groupings (by researchers in MMPbiology) are based partly on historical assessment of the substratespecificity of the MMP and partly on the cellular localization of theMMP. These groups are the collagenases, the gelatinases, thestromelysins, and the membrane type MMPs (MT-MMPs). It is becomingincreasingly clear that these divisions are somewhat artificial as thereare a number of MMPs that do not fit into any of the traditional groups.

The collagenases are capable of degrading triple helical fibrillarcollagens into distinctive ¾ and ¼ fragments. These collagens are themajor components of bone and cartilage, and MMPs are the only knownmammalian enzymes capable of degrading them. Traditionally, thecollagenases are: MMP-1 (Interstitial collagenase), MMP-8 (Neutrophilcollagenase), MMP-13 (Collagenase 3), MMP-18 (Collagenase 4), MMP-14(MT1-MMP) has also been shown to cleave fibrillar collagen, and morecontroversially there is evidence that MMP-2 is capable ofcollagenolysis.

The stromelysins display a broad ability to cleave ECM proteins but areunable to cleave the triple-helical fibrillar collagens. The threecanonical members of this group are: MMP-3 (Stromelysin 1), MMP-10(Stromelysin 2), and MMP-11 (Stromelysin 3). MMP-11 shows moresimilarity to the MT-MMPs, is convertase-activatable and is secretedtherefore usually associated to convertase-activatable MMPs.

The main substrates of gelatinases are type IV collagen and gelatin, andthese enzymes are distinguished by the presence of an additional domaininserted into the catalytic domain. This gelatin-binding region ispositioned immediately before the zinc binding motif, and forms aseparate folding unit which does not disrupt the structure of thecatalytic domain. The two members of this sub-group are: MMP-2 (72 kDagelatinase, gelatinase-A) and MMP-9 (92 kDa gelatinase, gelatinase-B).

The secreted MMPs include MMP-11 (Stromelysin 3), MMP-21 (X-MMP), andMMP-28 (Epilysin).

The membrane-bound MMPs include: the type-II transmembrane cysteinearray MMP-23, the glycosyl phosphatidylinositol-attached MMPs 17 and 25(MT4-MMP and MT6-MMP respectively), and the type-I transmembrane MMPs14, 15, 16, 24 (MT1-MMP, MT2-MMP, MT3-MMP, and MT5-MMP respectively).

All 6 MT-MMPs have a furin cleavage site in the pro-peptide, which is afeature also shared by MMP-11.

Other MMPs include MMP-12 (Macrophage metalloelastase), MMP-19 (RASI-1,occasionally referred to as stromelysin-4), Enamelysin (MMP-20), andMMP-27 (MMP-22, C-MMP), MMP-23A (CA-MMP), and MMP-23B.

Pharmaceutical Compositions and Administration

Once an imaging agent has been prepared or obtained, it may be combinedwith one or more pharmaceutically acceptable excipients to form apharmaceutical composition that is suitable for administering to asubject, including a human. As would be appreciated by one of skill inthis art, the excipients may be chosen, for example, based on the routeof administration as described below, the agent being delivered, timecourse of delivery of the agent, and/or the health/condition of thesubject.

Pharmaceutical compositions of the present invention and for use inaccordance with the present invention may include a pharmaceuticallyacceptable excipient or carrier. As used herein, the term“pharmaceutically acceptable excipient” or “pharmaceutically acceptablecarrier” means a non-toxic, inert solid, semi-solid or liquid filler,diluent, encapsulating material or formulation auxiliary of any type.Some examples of materials which can serve as pharmaceuticallyacceptable carriers are sugars such as lactose, glucose, and sucrose;starches such as corn starch and potato starch; cellulose and itsderivatives such as sodium carboxymethyl cellulose, ethyl cellulose, andcellulose acetate; powdered tragacanth; malt; gelatin; talc; excipientssuch as cocoa butter and suppository waxes; oils such as peanut oil,cottonseed oil; safflower oil; sesame oil; olive oil; corn oil andsoybean oil; glycols such as propylene glycol; esters such as ethyloleate and ethyl laurate; agar; detergents such as Tween 80; bufferingagents such as magnesium hydroxide and aluminum hydroxide; alginic acid;pyrogen-free water; isotonic saline; Ringer's solution; ethyl alcohol;and phosphate buffer solutions, as well as other non-toxic compatiblelubricants such as sodium lauryl sulfate and magnesium stearate, as wellas coloring agents, releasing agents, coating agents, sweetening,flavoring and perfuming agents, preservatives and antioxidants can alsobe present in the composition, according to the judgment of theformulator.

The pharmaceutical compositions of this invention can be administered tohumans and/or to animals parenterally such as intravenously,intranasally (via a nasal spray), and intraperitoneally. The mode ofadministration will vary depending on the intended use, as is well knownin the art. Alternatively, formulations of the present invention may beadministered parenterally as injections (intravenous, intramuscular, orsubcutaneous). These formulations may be prepared by conventional means,and, if desired, the subject compositions may be mixed with anyconventional additive.

Injectable preparations, for example, sterile injectable aqueous oroleaginous suspensions may be formulated according to the known artusing suitable dispersing or wetting agents and suspending agents. Thesterile injectable preparation may also be a sterile injectablesolution, suspension, or emulsion in a nontoxic parenterally acceptablediluent or solvent, for example, as a solution in 1,3-butanediol. Amongthe acceptable vehicles and solvents that may be employed are water,Ringer's solution, U.S.P. and isotonic sodium chloride solution. Inaddition, sterile, fixed oils are conventionally employed as a solventor suspending medium. For this purpose any bland fixed oil can beemployed including synthetic mono- or diglycerides. In addition, fattyacids such as oleic acid are used in the preparation of injectables.

The injectable formulations can be sterilized, for example, byfiltration through a bacteria-retaining filter, or by incorporatingsterilizing agents in the form of sterile solid compositions which canbe dissolved or dispersed in sterile water or other sterile injectablemedium prior to use.

The imaging agents of the invention may be provided in any suitableform, for example, in a pharmaceutically acceptable form. In some cases,the imaging agent is included in a pharmaceutically acceptablecomposition. In some embodiments, the imaging agent is provided as acomposition comprising ethanol, sodium ascorbate, and water. In somecases, the composition comprises less than 20 weight % ethanol, lessthan 15 weight % ethanol, less than 10 weight % ethanol, less than 8weight % ethanol, less than 6 weight % ethanol, less than 5 weight %ethanol, less than 4 weight % ethanol, less than 3 weight % ethanol, orless ethanol. In some cases, the composition comprises less than 100mg/mL, less than 75 mg/mL, less than 60 mg/mL, less than 50 mg/mL, lessthan 40 mg/mL, less than 30 mg/mL, or less sodium ascorbate in water. Ina particular non-limiting embodiment, the imaging agent is provided as asolution in water comprising less than 4% ethanol and less than 50 mg/mLsodium ascorbate in water.

The imaging agent composition for injection may be prepared in aninjection syringe. The imaging agent may be prepared by a radiopharmacy(e.g., using the methods described herein) and provided to a health-careprofessional for administration. In some aspects of the invention, theimaging agent is provided, for example, in a syringe or other container,with ≦50 mg/mL sodium ascorbate in water, ≦4 wt % ethanol, and about 1to 14 mCi of the imaging agent. In some aspects of the invention, theimaging agent is provided in a container such as a vial, bottle, orsyringe, and may be transferred, as necessary, into a suitablecontainer, such as a syringe for administration.

Syringes that include an adsorbent plunger tip may result in 10 to 25%of the imaging agent activity remaining in the syringe after injection.Syringes lacking an adsorbent plunger tip may be used, such as a 3 or 5mL NORM-JECT (Henke Sass Wolf, Dudley, Mass.) or other equivalentsyringe lacking an adsorbent plunger tip. Reduction of adsorption in thesyringe can increase the amount of the imaging agent that is transferredfrom the syringe and administered to the subject in methods of theinvention. A syringe used in methods of the invention may comprise theimaging agent, and be a non-adsorbing, or reduced adsorbent syringe. Insome embodiments a non-adsorbent or reduced-adsorbent syringe is asyringe that has been coated or treated to reduce the imaging agentadsorption. In some embodiments, a non-adsorbent or reduced-adsorbentsyringe is a syringe that lacks an adsorbent plunger tip. In someembodiments, a syringe used in conjunction with the invention adsorbsless than 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%,7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5% of the imaging agent it contains. Incertain aspects of the invention, a syringe that contains the imagingagent does not include a rubber or latex tip on the plunger. In somecases a syringe used in methods of the invention, includes a plungerthat adsorbs less than 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%,10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or 0.5% of the imaging agentthat the syringe contains. A syringe of the invention may also comprisesodium ascorbate, ethanol, and water, and certain embodiments of theinvention include a syringe containing the imaging agent in a solutioncomprising less than 4% ethanol and less than 50 mg/mL sodium ascorbatein water. A syringe of the invention may be a syringe that is latexfree, rubber free, and/or lubricant free. A syringe of the invention maycontain the imaging agent in an amount between about 1.5 and about 14mCi. A syringe of the invention may contain about 20 mCi or less of theimaging agent.

Components of a composition comprising the imaging agent may be selecteddepending on the mode of administration to the subject. Various modes ofadministration that effectively deliver imaging agents of the inventionto a desired tissue, cell, organ, or bodily fluid will be known to oneof ordinary skill in the art. In some embodiments, the imaging agent isadministered intravenously (e.g., intravenous bolus injection) usingmethods known to those of ordinary skill in the art. As used herein, adose that is “administered to a subject” means an amount of the imagingagent, e.g. the imaging agent that enters the body of the subject. Insome embodiments, due to factors such as partial retention of imagingagent such as the imaging agent in a syringe, tubing, needles, catheter,or other equipment used to administer the imaging agent to a subject,the amount of an imaging agent such as the imaging agent that ismeasured or determined to be in the a syringe or other equipmentprepared for administration may be more than the amount in the dose thatis administered to the subject. In some embodiments, an injection of animaging agent is followed by a flushing injection of normal saline, intothe subject, using the same tubing, needle, port, etc., used foradministration of the imaging agent. Flushing may be performedimmediately following administration of the imaging agent, or up to 1min, 2 min, 3 min, 5 min, or more, after the administration. The volumeof saline or other agent for flushing may be up to 5 ml, 6 ml, 7 ml, 8ml, 9 ml, 10 ml, 15 ml, 20 ml, or more. As will be understood by thoseof ordinary skill in the art, in embodiments where the imaging agent isadministered using a syringe or other container, the true amount of theimaging agent administered to the subject may be corrected for any theimaging agent that remains in the container. For example, the amount ofradioactivity remaining in the container, and tubing and needle ordelivery instrument that carried the imaging agent from the containerand into the subject can be determined after the imaging agent has beenadministered to the subject and the difference between the startingamount of radioactivity and the amount remaining after administrationindicates the amount that was delivered into the subject. In some cases,the container or injection device (e.g., catheter, syringe) may berinsed with a solution (e.g., saline solution) following administrationof the imaging agent.

In some embodiments of the invention, the total amount of the imagingagent administered to a subject over a given period of time, e.g., inone session, is less than or equal to about 50 mCi, less than or equalto 40 mCi, less than or equal to 30 mCi, less than or equal to 20 mCi,less than or equal to 18 mCi, less than or equal to 16 mCi, less than orequal to 15 mCi, less than or equal to 14 mCi, less than or equal to 13mCi, less than or equal to 12 mCi, less than or equal to 10 mCi, lessthan or equal to 8 mCi, less than or equal to 6 mCi, less than or equalto 4 mCi, less than or equal to 2 mCi, less than or equal to 1 mCi, lessthan or equal to 0.5 mCi. The total amount administered may bedetermined based on a single dose or multiple doses administered to asubject within a given time period of up to 1 minute, 10 minutes, 30minutes, 1 hour, 2 hours, 6 hours, 12 hours, 24 hours, 48 hours, ormore.

Based on radiation dose studies, the desirable maximum dose administeredto a subject may be based on determining the amount of the imaging agentwhich limits the radiation dose to about 5 rem to the critical organand/or about 1 rem effective dose (ED) or lower, as will be understoodby those of ordinary skill in the art. In a particular embodiment, thedesirable maximum dose or total amount of the imaging agent administeredis less than or equal to about 25 mCi, or less than or equal to about 14mCi over a period of time of up to 30 min, 1 hour, 2 hours, 6 hours, 12hours, 24 hours, 48 hours, or more. In some embodiments, the maximumdose of the imaging agent administered to a subject may be less than 3.5μg per 50 kg of body weight per day. That is, in some embodiments of theinvention, the maximum dose of the imaging agent administered to asubject may be less than about 0.07 μg of the imaging agent per kg ofbody weight per day.

Abbreviations

The following abbreviations are used herein:

-   Acm acetamidomethyl-   b-Ala, beta-Ala or bAla 3-aminopropionic acid-   ATA 2-aminothiazole-5-acetic acid or 2-aminothiazole-5-acetyl group-   Boc t-butyloxycarbonyl-   CBZ, Cbz or Z Carbobenzyloxy-   Cit citrulline-   Dap 2,3-diaminopropionic acid-   DCC dicyclohexylcarbodiimide-   DIEA diisopropylethylamine-   DMAP 4-dimethylaminopyridine-   EOE ethoxyethyl-   HBTU 2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronium    hexafluorophosphate-   hynic boc-hydrazinonicotinyl group or    2-[[[5-[carbonyl]-2-pyridinyl]hydrazono]methyl]-benzenesulfonic    acid,-   NMeArg or MeArg a-N-methyl arginine-   NMeAsp a-N-methyl aspartic acid-   NMM N-methylmorpholine-   OcHex O-cyclohexyl-   OBzl O-benzyl-   oSu O-succinimidyl-   TBTU 2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronium    tetrafluoroborate-   THF tetrahydrofuranyl-   THP tetrahydropyranyl-   Tos tosyl-   Tr trityl

The following conventional three-letter amino acid abbreviations areused herein; the conventional one-letter amino acid abbreviations arenot used herein:

Ala=alanine Arg=arginine Asn=asparagine Asp=aspartic acid Cys=cysteineGln=glutamine Glu=glutamic acid Gly=glycine His=histidine Ile=isoleucineLeu=leucine Lys=lysine Met=methionine Nle=norleucine Orn=ornithinePhe=phenylalanine Phg=phenylglycine Pro=proline Sar=sarcosine Ser=serineThr=threonine Trp=tryptophan Tyr=tyrosine Val=valine.

EXAMPLES Example 1

We have established the feasibility of in vivo imaging of MMP activationin pigs (Sahul et al. Circ Cardiovasc Imaging 2011, 4:381-391) and dogs(Liu et al. J Nucl Med 2011, 52(3):453-60) post-MI. The data derived inpigs involved surgical occlusion of two marginal branches of the leftcircumflex artery and resulted in regional activation of MMPs in theinferolateral wall. (Sahul et al. Circ Cardiovasc Imaging 2011,4:381-391). This surgical model caused significant activation of MMPs inthe surgical wound adjacent to both the atria and ventricles of heart,complicating in vivo imaging. The studies in dogs employed percutaneousballoon occlusion of left anterior descending artery, avoided thesurgical intervention, and resulted in improved image quality. In theserecently published porcine studies with serial SPECT/CT imaging, wedemonstrated focal uptake of the MMP-targeted agent ^(99m)Tc-RP805within the infarcted lateral wall, which peaked at ˜2 weeks post injury,and remained elevated at 4 weeks post occlusion. Early MMP activity at 1week post-MI predicted late post MI ventricular remodeling (FIG. 1).

Example 2

Heart failure after MI leads to atrial remodeling and fibrosis, therebyincreasing vulnerability to AF. The role of atrial MMP activation hasnot been well studied. We hypothesized that atrial structural remodelingand fibrillation vulnerability occurring early after MI can benoninvasively assessed using targeted molecular imaging of MMPactivation.

Methods:

In vivo and ex vivo SPECT/CT images were obtained in control pigs (n=7)and in pigs 10 days (n=6) or 4 weeks (n=6) after surgical induction ofMI. MI was induced by surgical ligation of two marginal branches of theleft circumflex coronary artery. Animals were injected intravenouslywith a ^(99m)Tc-labeled radiotracer (^(99m)Tc-RP805) targeted toactivated MMPs. Hybrid 64-slice SPECT/CT scans were acquired at 2 hoursafter injection of a ^(99m)Tc-RP805. X-ray CT imaging with contrast wasperformed to define coronary anatomy and cardiac chambers.

After sacrifice, hearts were excised and cast in alginate for ex vivoSPECT/CT imaging.Myocardial ^(99m)Tc-RP805 retention in the atria and the ventricles wasquantified by gamma well counting after sacrifice. AF vulnerability wasassessed in subsets of control pigs (n=5) and in pigs 4 weeks post-MI(n=4) using atrial burst pacing for 10 seconds with cycle lengthsranging from 300 to 180 ms.

Results:

In vivo and ex vivo SPECT/CT imaging demonstrated increased^(99m)Tc-RP805 retention in the MI region and both atria compared tocontrol pigs. At 10 days post-MI, ^(99m)Tc-RP805 retention (% injecteddose/gram) was increased ˜6-fold in the MI region and ˜3-fold in theleft atrium (LA) compared to control regions (p<0.01 each, FIG. 2,bottom panel). At 4 weeks post-MI, 99Tc-RP805 retention was increased˜4-fold in the MI region and ˜2-fold in the LA compared to controlregions (p<0.01 each, FIG. 2, bottom panel). AF was inducible in 4 of 4pigs at 4 weeks post-MI and 0 of 5 controls (p<0.01). Representative invivo and ex vivo images at 10 days post-MI are shown in FIG. 2, top andmiddle panels.

Table 1 shows that AF burden is significantly increased at four weekspost-MI in our post-MI HF model. Following 10 seconds of burst pacing atcycle lengths ranging from 260-180 ms, the duration of AF in post-MIanimals was 2.0±1.8 minutes. No AF could be induced in the control groupdespite pacing down to a cycle length of 180 ms.

TABLE 1 AF duration Burst Cycle Length (sec) (ms) p-value Control (n =3) 0.0 215 ± 30 4-week HF (n = 4) 2.0 ± 1.8 <180 0.03

Conclusions:

MMP-targeted SPECT/CT imaging provides a valuable noninvasive approachfor assessment of atrial remodeling and allows early identification ofarrhythmogenic substrates prior to the onset of irreversible fibrosis.In vivo imaging of MMP activation has significant clinical implicationsregarding risk stratification and directing pharmacological andinterventional treatments of AF.

Example 3

A cohort of patients post cardioversion are administered an effectiveamount of the imaging agent of the invention, images of each patient'sleft atrium are obtained and the uptake of the imaging agent isquantified. A cut point for imaging agent uptake is then establishedsuch that the cut point separates the cohort into 2 populations; thoseabove the cut point have recurrent AF while those below the cut point donot.

Based on the cut point levels determined above, future patients are thentested for MMP levels using the methods of the invention and thosedemonstrating above cut point levels are treated using one or more ofthe therapies described herein and known in the art for AF, includingbut not limited to pharmacological rate control therapy, pharmacologicalrhythm control therapy, ablation, and/or implantable pacer.

Example 4

A cohort of patients with a recent history of myocardial infarction areadministered an effective amount of the imaging agent of the invention,images of each patient's left atrium are obtained and the uptake of theimaging agent is quantified. The patients also undergo a restingflurpiridaz F 18 myocardial perfusion study and the summed rest scoredetermined for each patient. Logistic regression analysis is performedto produce an equation expressing the likelihood of future AF as afunction of summed rest score and quantified imaging agent uptake.

Example 5 Part A Preparation of Imaging Agent 1

Methyl(3S,7S,6R)-4-aza-7-[(tert-butyl)oxycarbonyl]-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-3-carboxylatewas prepared according to the method of Xue, et al. (J. Med. Chem. 2001,44, 2636-2660) then transformed into Imaging Agent 1 through theconvergent assembly of O-(tetrahydro-2H-pyran-2-yl)hydroxylamine and3-fluoropropan-1-amine using standard protecting group strategy (Wuts,P. G. M.; Greene, T. W. The Role of Protective Groups in OrganicSynthesis. In Greene's Protective Group in Organic Synthesis, FourthEdition; John Wiley & Sons, Inc.: Hoboken, N.J., 2007; pp 1-15) andpeptide coupling chemical methods (Tsuda, Y; Okada, Y. Solution-PhasePeptide Synthesis. In Amino Acids, Peptides and Proteins in OrganicChemistry: Building Blocks, Catalysis and Coupling Chemistry, Volume 3;Hughes, A. B. Ed.; Wiley-VCH Verlag GmbH & Co. KgaA: Weinheim, Germany,2010; 201-251) commonly known to those skilled in the art.

Part B Preparation of Imaging Agent 2

Methyl(3S,7S,6R)-4-aza-7-[(tert-butyl)oxycarbonyl]-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-3-carboxylatewas prepared according to the method of Xue, et al. (J. Med. Chem. 2001,44, 2636-2660) then transformed into Imaging Agent 2 through theconvergent assembly of O-(tetrahydro-2H-pyran-2-yl)hydroxylamine and6-aminohexan-1-ol using standard protecting group strategy, peptidecoupling, and fluorination chemical methods commonly known to thoseskilled in the art.

Part C Preparation of Imaging Agent 3

Methyl(3S,7S,6R)-4-aza-7-[(tert-butyl)oxycarbonyl]-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-3-carboxylatewas prepared according to the method of Xue, et al. (J. Med. Chem. 2001,44, 2636-2660) then transformed into Imaging Agent 3 through theconvergent assembly of O-(tetrahydro-2H-pyran-2-yl)hydroxylamine,2-((tert-butoxycarbonyl)amino)acetic acid and 3-fluoropropan-1-amineusing standard protecting group strategy and peptide coupling chemicalmethods commonly known to those skilled in the art.

Part D Preparation of Imaging Agent 4

Methyl(3S,7S,6R)-4-aza-7-[(tert-butyl)oxycarbonyl]-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-3-carboxylatewas prepared according to the method of Xue, et al. (J. Med. Chem. 2001,44, 2636-2660) then transformed into Imaging Agent 4 through theconvergent assembly of O-(tetrahydro-2H-pyran-2-yl)hydroxylamine,2-((tert-butoxycarbonyl)amino)acetic acid and 5-aminopentan-1-ol usingstandard protecting group strategy, peptide coupling, and fluorinationchemical methods commonly known to those skilled in the art.

Part E Preparation of Imaging Agent 5

Methyl(3S,7S,6R)-4-aza-7-[(tert-butyl)oxycarbonyl]-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-3-carboxylatewas prepared according to the method of Xue, et al. (J. Med. Chem. 2001,44, 2636-2660) then transformed into Imaging Agent 5 through theconvergent assembly of O-(tetrahydro-2H-pyran-2-yl)hydroxylamine and(4-fluorophenyl)methanamine using standard protecting group strategy andpeptide coupling chemical methods commonly known to those skilled in theart.

Part F Preparation of Imaging Agent 6

Methyl(3S,7S,6R)-4-aza-7-[(tert-butyl)oxycarbonyl]-6-(2-methylpropyl)-11-oxa-5-oxobicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-3-carboxylate was prepared according to the methodof Xue, et al. (J. Med. Chem. 2001, 44, 2636-2660) then transformed intoImaging Agent 6 through the convergent assembly ofO-(tetrahydro-2H-pyran-2-yl)hydroxylamine, and(4-(3-fluoropropoxy)phenyl)methanamine using standard protecting groupstrategy and peptide coupling chemical methods commonly known to thoseskilled in the art. (4-(3-Fluoropropoxy)phenyl)methanamine was preparedfrom 4-hydroxybenzonitrile and 1-bromo-3-fluoropropane.

Example 6 In-Vitro MMP Inhibition Assay

Individual inhibitors were dissolved in TCN buffer (50 mM Tris-HCl, 10mM CaCl₂, 150 mM NaCl₂, 0.05% Brij 35 at pH 7.5) at appropriatedilutions then added to the wells of a microtiter plate (10 μL/well) intriplicate. Each well of test agent (and appropriate control wells) wasthen treated with activated MMP-2 or 9 (10 μL of a 40 nM solution in 50mM Hepes, 10 mM CaCl₂, 1% Brij 35 at pH 7.5; R&D Systems) followed by 30μL TCN buffer and 150 μL the fluorogenic peptide substrate(Mca-PLGL-Dpa-AR-NH₂; R&D Systems). The resulting mixtures wereincubated 1 h at 27° C. then analyzed using a FL600 fluorescent platereader (excitation=310/20; emission=420/50; optics=bottom;sensitivity=225) and KC4 Software.

TABLE 2 MMP inhibition data Imaging Agent MMP-2 MMP-9 1 5.19 3.54 2 31.620.2 3 4.61 2.59 4 15.4 15.3 5 0.58 0.74 6 2.74 2.98 RP805 6.50 7.40

Example 7

FIG. 3 shows representative transaxial slices from ex vivo SPECT imagesof a control pig heart, and hearts from pigs at 1 and 2 weeks post-MI.the top row of each image set are targeted ^(99m)Tc-RP805 images (lineargrey scale) matched with corresponding high resolution CT images (grayscale, below). Hearts were filled with alginate mixed with CT contrastto define right and left ventricles (RV & LV) and atria (RA & LA).Uniform uptake is seen in the control heart. Infarcted heartsdemonstrate focal ^(99m)Tc-RP805 in both the infarct region and atria.

FIG. 4 shows results from quantitative analysis of ex vivo^(99m)Tc-RP805 SPECT images from a pig heart at 4 weeks post-MI. A.Uncorrected SPECT images, B. SPECT images with resolution recovery, C.SPECT data reconstructed with partial volume correction (PVC), D. Greyscale-coded ^(99m)Tc-RP805 activity for 8 radial sectors per slice fromgamma well counter, E. Postmortem images of heart demonstrating denseinferolateral scar and marked wall thinning, F. Correlation betweenmeasured regional myocardial well-counter activity and SPECT derivedactivity with PVC.

FIG. 5 shows a plot of the MMP total activity per unit time, accordingto some embodiments.

FIG. 6 shows a plot of the percent area collagen for the left and rightregions of the heart. Regional changes in matrix structure could bedetected by 1 week post-MI which were significant by 4 weeks post-MI(Kruskal-Wallis, p<0.05). In the inset: PSR imaging revealed matrixdisruption and discontinuity between atrial myocytes which wasprogressive with time post-MI.

Example 8

Calcific aortic valve disease (CAVD) is common among the elderlypopulation. Inflammation and matrix remodeling play a central role inthe progression of CAVD to symptomatic aortic stenosis. Matrixmetalloproteinases (MMPs) are upregulated in CAVD. In vivo imaging ofMMP activation may lead to prospective identification of aortic valvesthat are at high risk for developing stenosis and help track the effectof potential novel therapeutic interventions. This example illustratesuse of an MMP-targeted agent for both in vivo imaging and definition oftemporal patterns of MMP activation in CAVD.

Methods and Results:

ApoE^(−/−) mice were fed a high fat diet (HFD) for up to 9 months.Histological analysis of the aortic valve showed considerable thickeningof valve leaflets over time. M mode echocardiography demonstrated areduction in leaflet separation from 3 months to 9 months. Non-contrasthigh resolution CT established the presence of aortic valvecalcification after 9 months of HFD. MMP-targeted microSPECT imagingusing ^(99m)Tc-RP805, a tracer with specificity for activated MMPs,followed by CT angiography showed considerable tracer uptake (in countsper voxel per MBq injected dose) in the aortic valve area at 3, 6 and 9months. Uptake was maximal after 6 months of HFD (3 m: 0.047±0.002, n=2,6 m: 0.102±0.013, n=4, 9 m: 0.064±0.004, n=4). Tracer uptake in theaortic valve area was confirmed following ex vivo planar imaging.

Conclusion:

MMP-targeted microSPECT/CT imaging can detect aortic valve biology inCAVD in vivo. In this model, protease activation in the aortic valve ismaximal at 6 months and declines with progression of CAVD.

FIG. 7 shows ^(99m)Tc-RP805 in vivo microSPECT/CT imaging (left) of MMPactivation in an ApoE−/− mouse fed a Western diet for 9 months. Traceruptake in the aortic valve area is indicated by the arrows. Uptake inthe aortic valve was confirmed by ex vivo planar imaging (right) of theexplanted heart and aorta.

FIG. 8 shows in vivo uptake of ^(99m)Tc-RP805 in the aortic valve overtime in ApoE^(−/−) mice fed a Western diet.

FIG. 9 shows ex vivo uptake of ^(99m)Tc-RP805 in the aortic valve overtime in ApoE^(−/−) mice fed a Western diet.

FIG. 10 shows autoradiography of the explanted aorta from an ApoE−/−mouse fed a Western diet for three months. Arrows indicate uptake of¹¹¹In-RP782 in the aortic valve area.

FIG. 11 shows H&E staining of the aortic valve in ApoE−/− mice fed aWestern diet for 4 (left) and 9 months (right) demonstrating markedremodeling of valve leaflets over time.

FIG. 12 shows immunostaining of F4-80 (dark grey) in the aortic valvefrom an ApoE−/− mouse fed a Western diet for 6 months demonstratingconsiderable macrophage infiltration.

FIG. 13 shows plots of aortic valve GAPDH-normalized CD68 (top) andMMP-12 (bottom) mRNA expression quantified by real time RT-PCR in wildtype (WT) mice on normal chow and ApoE−/− mice fed a Western diet for 3,6 or 9 months.

FIG. 14 shows grey scale-coded non contrast CT images of an ApoE−/−mouse fed a Western diet for 10 months demonstrating calcification ofthe aortic valve. Arrows indicate the aortic valve plane.

FIG. 15 shows M mode echocardiographic images of ApoE−/− mice fed aWestern diet demonstrating normal systolic separation of aortic valvecusps after 3 months on diet (left) and reduced separation after 9months (right).

Example 9

Atherosclerosis, a major cause of morbidity and mortality in the US, islinked to hyperlipidemia. Pharmacologic treatment of hyperlipidemia is amainstay of modern treatment for atherosclerotic diseases and isbelieved to be related at least in part to “stabilizing” effects onplaque biology. This example investigates the effect of anti-lipidtherapies on plaque biology through serial imaging of matrixmetalloproteinase (MMP) activation in vivo.

Methods:

ApoE^(−/−) mice were fed a high fat diet (HFD) for 2 months to induceatherosclerosis. After two months, the mice were randomly assigned toone of 4 groups: HFD, HFD plus simvastatin (Sim), HFD plus fenofibrate(Fen) and high fat withdrawal (HFW). MicroSPECT/CT imaging using^(99m)Tc-RP805, a tracer with specificity for activated MMPs wasperformed after one week and 4 weeks.

Results:

Withdrawal of the HFD significantly reduced total cholesterol levels at1 week (1845.1±41.9 to 492.7±19.4 mg/dL, p=0.001). Neither simvastatinnor fenofibrate had a significant effect on total cholesterol levelcompared to animals on HFD at one week, but both significantly reducedcholesterol levels by 4 weeks. At 1 week, there was no significantdifference in uptake of ^(99m)Tc-RP805 in the aortic arch betweendifferent experimental groups. Uptake (in counts per voxel per mCiinjected dose) at 4 weeks however, was significantly higher in the HFDgroup compared to other three groups (HFD: 4.99±0.27, n=5, Sim:3.17±0.52, n=6, p<0.02, Fen: 2.23±0.28, n=7, p<0.001, HFW: 1.77±0.22,n=5, p<0.001). ^(99m)Tc-RP805 uptake in the aortic arch significantlyincreased from 1 week to 4 weeks in animals on HFD (mean uptake2.84±0.47 versus 4.99±0.27, p<0.003), but did not occur in the otherexperimental groups.

Conclusions:

MMP-targeted molecular imaging demonstrates an effect of anti-lipidtherapies on plaque biology at 4 weeks, but not at 1 week afterinitiation of therapy.

Example 10 Tissue Biodistribution

Oncomice®, obtained through an in-house breeding program, wereanesthetized intramuscularly with 0.1 mL of ketamine/acepromazine (1.8mL saline, 1.0 mL ketamine, and 0.2 mL acepromazine) prior to dosing andtissue sampling. Individual mice were then injected via the tail veinwith an imaging agent of the present invention (0.5-2.0 mCi/kg in 0.1mL). Mice were euthanized and biodistribution performed at 1 hpost-injection. Selected tissues were removed, weighed, and counted on agamma counter. Results are expressed as the percentage of injected doseper gram tissue (mean±SEM; Table 3).

TABLE 3 Summary of imaging agent distribution in the Oncomonse ® ImagingAgent Distribution (% ID/g) tissue 2 4 6 blood 1.07 ± 0.060 0.41 ± 0.0990.88 ± 0.061 heart 0.95 ± 0.065 0.36 ± 0.064 0.69 ± 0.073 lung 0.97 ±0.121 0.45 ± 0.071 1.69 ± 0.382 liver 13.1 ± 2.17 23.6 ± 5.19 11.3 ±1.73 spleen 0.69 ± 0.085 0.34 ± 0.057 0.81 ± 0.021 kidney 20.6 ± 3.2514.8 ± 1.79 6.66 ± 1.46 bone 2.02 ± 0.320 1.28 ± 0.200 2.86 ± 0.124muscle 0.50 ± 0.073 0.17 ± 0.043 0.44 ± 0.049 urine 71.8 7.67 ± 5.007.21 ± 6.71 tumor 0.95 ± 0.103 1.12 ± 0.204 0.73 ± 0.026

EQUIVALENTS

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of skill in the artto which the disclosed methods and compositions belong.

Throughout this application, various publications are referenced. Thedisclosures of these publications in their entireties are herebyincorporated by reference into this application in order to more fullydescribe the state of the art to which this pertains. The referencesdisclosed are also individually and specifically incorporated byreference herein for the material contained in them that is discussed inthe sentence in which the reference is relied upon.

It must be noted that as used herein and in the appended claims, thesingular forms “a,” “an,” and “the” include plural reference unless thecontext clearly dictates otherwise. Thus, for example, reference to “anMMP” includes a plurality of such MMPs, reference to “the MMP” is areference to one or more MMP and equivalents thereof known to thoseskilled in the art, and so forth.

“Optional” or “optionally” means that the subsequently described event,circumstance, or material may or may not occur or be present, and thatthe description includes instances where the event, circumstance, ormaterial occurs or is present and instances where it does not occur oris not present.

Throughout the description and claims of this specification, the word“comprise” and variations of the word, such as “comprising” and“comprises,” means “including but not limited to” and is not intended toexclude, for example, other additives, components, integers or steps.

What is claimed is:
 1. A method of evaluating risk of developing atrialfibrillation comprising administering to a subject an imaging agentcomprising a matrix metalloproteinase (MMP) inhibitor linked to animaging moiety, and acquiring a cardiac image of the subject, wherein alevel of the imaging agent in the heart of the subject above control isindicative of an increased risk of developing atrial fibrillation.
 2. Amethod for evaluating risk of developing atrial fibrillation recurrencecomprising administering to a subject previously diagnosed with atrialfibrillation and previously treated for atrial fibrillation an imagingagent comprising a matrix metalloproteinase (MMP) inhibitor linked to animaging moiety, and acquiring a cardiac image of the subject, wherein alevel of imaging agent in the heart of the subject above control isindicative of an increased risk of atrial fibrillation recurrence. 3.The method of claim 2, wherein the atrial fibrillation recurrence isatrial fibrillation recurrence following cardioversion therapy.
 4. Amethod for identifying a subject having a history of atrial fibrillationthat is likely to respond to treatment with an implantable pacer,pharmacological rate control therapy, pharmacological rhythm controltherapy, or ablation therapy comprising administering to a subjectpreviously diagnosed with atrial fibrillation an imaging agentcomprising a matrix metalloproteinase (MMP) inhibitor linked to animaging moiety, and acquiring a cardiac image of the subject, wherein alevel of imaging agent in the heart of the subject above controlidentifies a subject to be treated with an implantable pacer. 5-7.(canceled)
 8. The method of claim 4, wherein the subject has experiencedone AF event.
 9. The method of claim 4, wherein the subject hasexperienced recurrent AF.
 10. The method of claim 1, wherein the cardiacimage is an atrial image.
 11. The method of claim 10, wherein thecardiac image is a left atrial image.
 12. The method of claim 1, whereinthe subject is a human subject.
 13. The method of claim 1, wherein thesubject does not manifest signs associated with myocardial fibrosis. 14.The method of claim 1, wherein the subject does not manifest signsassociated with myocardial remodeling.
 15. The method of claim 1,wherein the subject has experienced a myocardial infarction.
 16. Themethod of claim 1, wherein the imaging agent is RP805.
 17. The method ofclaim 1, wherein the imaging agent is selected from the group consistingof

wherein F represents an isotopically-enriched population of ¹⁸F, andvariants thereof comprising, instead of F, an isotopically-enrichedimaging moiety selected from the group consisting of ¹¹C, ¹³N, ¹²³I,¹²⁵I, ^(99m)Tc, ⁹⁵Tc, ¹¹¹In, ⁶²Cu, ⁶⁴Cu, ⁶⁷Ga, and ⁶⁸Ga.
 18. The methodof claim 1, further comprising determining a measure of myocardialperfusion in the subject.
 19. The method of claim 18, whereindetermining a measure of myocardial perfusion in the subject comprisesadministering to the subject a myocardial perfusion imaging agent andobtaining a myocardial perfusion image to determine a measure ofmyocardial perfusion.